);
}
/* ---------- 1. Bradford Factor ---------- */
function BradfordCalc() {
const [spells, setSpells] = React.useState(4);
const [days, setDays] = React.useState(7);
const S = Number(spells) || 0, D = Number(days) || 0;
const score = S * S * D;
const band = score >= 900 ? ['Very high', 'danger'] : score >= 450 ? ['High', 'warning'] : score >= 150 ? ['Moderate', 'warning'] : ['Low', 'success'];
return (
{ setSpells(4); setDays(7); }}
inputs={}
result={}
explanation={The score is S² × D, where S is the number of separate absence spells and D the total days absent. Here: {S} × {S} × {D} = {score.toLocaleString('en-GB')}. Squaring the spell count is what penalises repeated short absences.} />
);
}
/* ---------- 2. Holiday entitlement ---------- */
function HolidayCalc() {
const [mode, setMode] = React.useState('Days per week');
const [daysPerWeek, setDaysPerWeek] = React.useState(5);
const [hoursPerWeek, setHoursPerWeek] = React.useState(37.5);
const [monthsWorked, setMonthsWorked] = React.useState(12);
const dpw = Math.min(Number(daysPerWeek) || 0, 5);
const hpw = Number(hoursPerWeek) || 0;
const months = Math.min(Math.max(Number(monthsWorked) || 0, 0), 12);
const proRata = months / 12;
const statutoryDays = Math.min(dpw * 5.6, 28);
const entitlementDays = statutoryDays * proRata;
const entitlementHours = hpw * 5.6 * proRata;
const isHours = mode === 'Hours per week';
return (
{ setMode('Days per week'); setDaysPerWeek(5); setHoursPerWeek(37.5); setMonthsWorked(12); }}
inputs={
{isHours
?
: }
}
result={}
explanation={isHours
? Hours per week × 5.6 weeks × (months ÷ 12). Here: {hpw} × 5.6 × {proRata.toFixed(3)} = {entitlementHours.toFixed(1)} hours.
: Days per week × 5.6 weeks, capped at 28 days, then pro-rated. Here: {dpw} × 5.6 = {(dpw * 5.6).toFixed(1)}, capped to {statutoryDays.toFixed(1)}, × {proRata.toFixed(3)} = {entitlementDays.toFixed(1)} days.} />
);
}
/* ---------- 3. Salary / take-home (England & NI, 2025/26 thresholds) ---------- */
const TAX = {
personalAllowance: 12570, taperStart: 100000,
basicTo: 50270, higherTo: 125140,
basicRate: 0.20, higherRate: 0.40, additionalRate: 0.45,
niPrimary: 12570, niUpper: 50270, niMain: 0.08, niUpperRate: 0.02
};
function incomeTax(gross) {
const allowance = gross > TAX.taperStart
? Math.max(0, TAX.personalAllowance - (gross - TAX.taperStart) / 2)
: TAX.personalAllowance;
const taxable = Math.max(0, gross - allowance);
const basicBand = Math.max(0, TAX.basicTo - TAX.personalAllowance);
const higherBand = Math.max(0, TAX.higherTo - TAX.basicTo);
const basic = Math.min(taxable, basicBand);
const higher = Math.min(Math.max(taxable - basicBand, 0), higherBand);
const additional = Math.max(taxable - basicBand - higherBand, 0);
return {
allowance,
basic: basic * TAX.basicRate,
higher: higher * TAX.higherRate,
additional: additional * TAX.additionalRate,
total: basic * TAX.basicRate + higher * TAX.higherRate + additional * TAX.additionalRate
};
}
function employeeNI(gross) {
const main = Math.min(Math.max(gross - TAX.niPrimary, 0), TAX.niUpper - TAX.niPrimary) * TAX.niMain;
const upper = Math.max(gross - TAX.niUpper, 0) * TAX.niUpperRate;
return main + upper;
}
function SalaryCalc() {
const [gross, setGross] = React.useState(35000);
const [pension, setPension] = React.useState(5);
const g = Number(gross) || 0;
const pensionPct = Number(pension) || 0;
const pensionAmt = g * pensionPct / 100;
const taxableBase = Math.max(0, g - pensionAmt);
const tax = incomeTax(taxableBase);
const ni = employeeNI(g);
const net = g - pensionAmt - tax.total - ni;
return (
{ setGross(35000); setPension(5); }}
inputs={}
result={}
explanation={Pension is deducted first, then income tax is applied band by band to what remains above the personal allowance, and National Insurance is charged on gross pay. Tax here: {gbp(tax.basic)} basic + {gbp(tax.higher)} higher + {gbp(tax.additional)} additional = {gbp(tax.total)}.} />
);
}
/* ---------- 4. Hourly rate ---------- */
function HourlyCalc() {
const [salary, setSalary] = React.useState(32000);
const [hours, setHours] = React.useState(37.5);
const [weeks, setWeeks] = React.useState(52);
const s = Number(salary) || 0, h = Number(hours) || 0, w = Number(weeks) || 52;
const annualHours = h * w;
const rate = annualHours > 0 ? s / annualHours : 0;
const nmw = 12.21;
return (
{ setSalary(32000); setHours(37.5); setWeeks(52); }}
inputs={}
result={= nmw ? 'Above (' + gbp(nmw) + ')' : 'BELOW (' + gbp(nmw) + ')']
]}
note={rate < nmw && rate > 0
? 'This rate is below the April 2025 National Living Wage of £12.21 for workers aged 21 and over. Check the contract and hours.'
: 'National Living Wage from April 2025 is £12.21 for ages 21 and over. Lower rates apply to younger workers and apprentices.'} />}
explanation={Salary ÷ (hours per week × paid weeks). Here: {gbp0(s)} ÷ ({h} × {w} = {annualHours.toFixed(1)} hours) = {gbp(rate)} per hour.} />
);
}
/* ---------- 5. Statutory notice period ---------- */
function NoticeCalc() {
const [years, setYears] = React.useState(4);
const [months, setMonths] = React.useState(0);
const y = Math.max(0, Number(years) || 0);
const m = Math.max(0, Number(months) || 0);
const totalMonths = y * 12 + m;
let notice, basis;
if (totalMonths < 1) { notice = 'None'; basis = 'Under one month of service'; }
else if (totalMonths < 24) { notice = '1 week'; basis = 'One month to under two years'; }
else { const wks = Math.min(Math.floor(totalMonths / 12), 12); notice = wks + ' weeks'; basis = 'One week per full year, capped at 12'; }
return (
{ setYears(4); setMonths(0); }}
inputs={}
result={= 1 ? '1 week minimum' : 'None']]}
note="This is the statutory floor. Contractual notice is often longer and takes precedence when more generous. Notice rules do not apply to gross misconduct dismissals." />}
explanation={Under one month: none. One month to under two years: one week. Two years or more: one week per complete year, capped at twelve. Here {totalMonths} months of service gives {notice}.} />
);
}
/* ---------- 6. Employee cost (employer view) ---------- */
function EmployeeCostCalc() {
const [salary, setSalary] = React.useState(35000);
const [pension, setPension] = React.useState(3);
const [extras, setExtras] = React.useState(1200);
const s = Number(salary) || 0;
const pensionPct = Number(pension) || 0;
const secondaryThreshold = 5000;
const employerNIRate = 0.15;
const employerNI = Math.max(0, s - secondaryThreshold) * employerNIRate;
const pensionCost = Math.max(0, s - 6240) * pensionPct / 100;
const other = Number(extras) || 0;
const total = s + employerNI + pensionCost + other;
const uplift = s > 0 ? ((total / s - 1) * 100) : 0;
return (
{ setSalary(35000); setPension(3); setExtras(1200); }}
inputs={}
result={}
explanation={Employer NI is 15% of salary above the £5,000 secondary threshold. Pension is {pensionPct}% of qualifying earnings above £6,240. Adding other costs: {gbp0(s)} + {gbp(employerNI)} + {gbp(pensionCost)} + {gbp0(other)} = {gbp0(total)}.} />
);
}
/* ---------- 7. Overtime ---------- */
function OvertimeCalc() {
const [rate, setRate] = React.useState(14.5);
const [hours, setHours] = React.useState(6);
const [multiplier, setMultiplier] = React.useState('1.5');
const r = Number(rate) || 0, h = Number(hours) || 0, m = Number(multiplier) || 1;
const otRate = r * m;
const pay = otRate * h;
return (
{ setRate(14.5); setHours(6); setMultiplier('1.5'); }}
inputs={}
result={}
explanation={Hourly rate × multiplier × hours. Here: {gbp(r)} × {m} = {gbp(otRate)} per hour, × {h} hours = {gbp(pay)}.} />
);
}
/* ---------- 8. Payroll cost of a team ---------- */
function PayrollCalc() {
const [employees, setEmployees] = React.useState(25);
const [avgSalary, setAvgSalary] = React.useState(31000);
const [pension, setPension] = React.useState(3);
const n = Number(employees) || 0, avg = Number(avgSalary) || 0;
const pensionPct = Number(pension) || 0;
const salaryTotal = n * avg;
const niTotal = n * Math.max(0, avg - 5000) * 0.15;
const pensionTotal = n * Math.max(0, avg - 6240) * pensionPct / 100;
const total = salaryTotal + niTotal + pensionTotal;
return (
{ setEmployees(25); setAvgSalary(31000); setPension(3); }}
inputs={}
result={ 0 ? total / n : 0)]
]}
note="A planning estimate using flat averages and 2025/26 employer rates. Real payroll varies with individual salaries, tax codes, benefits and Employment Allowance eligibility." />}
explanation={Each employee costs their salary, plus 15% employer NI above £5,000, plus {pensionPct}% pension above £6,240. Multiplied across {n} employees at an average of {gbp0(avg)}: {gbp0(total)} a year.} />
);
}
/* One page per calculator. Copy restates the formulas and notes above; rates
named here must change together with the constants in each calculator. */
const CALCULATORS = [
{
id: 'bradford', file: 'calc-bradford-factor.html', name: 'Bradford Factor', icon: 'Activity', Calc: BradfordCalc,
blurb: 'Score absence patterns with the S² × D formula.',
intro: 'Work out an employee’s Bradford Factor score from the number of absence spells and total days absent. Free, instant, and nothing you enter leaves your browser.',
about: [
'The Bradford Factor scores absence so that frequent short absences weigh more than one long one. The score is S² × D: the number of separate absence spells, squared, multiplied by the total days absent in the period — usually a rolling 12 months.',
'Squaring the spell count is the whole point. One absence of ten days scores 1 × 1 × 10 = 10. Five separate two-day absences — the same ten days — score 5 × 5 × 10 = 250.',
'Treat the score as a prompt for a conversation, not a verdict. A disability or long-term condition can cause frequent short absences, so acting on the score alone carries a discrimination risk.'
],
faqs: [
{ q: 'How is the Bradford Factor calculated?', a: 'Square the number of separate absence spells (S) and multiply by the total days absent (D): S² × D. Four spells totalling seven days gives 4 × 4 × 7 = 112.' },
{ q: 'What is a high Bradford Factor score?', a: 'Trigger points are set by each employer’s absence policy. Common thresholds are 150, 450 and 900, but they should prompt a conversation rather than an automatic sanction.' },
{ q: 'What counts as one absence spell?', a: 'Each unbroken period of absence counts as one spell, however many days it lasts.' },
{ q: 'Can the Bradford Factor be discriminatory?', a: 'It can be if used without judgement. A disability or health condition may cause frequent short absences and a high score, so the score alone should never be grounds for action.' }
]
},
{
id: 'holiday', file: 'calc-holiday-entitlement.html', name: 'Holiday Entitlement', icon: 'Plane', Calc: HolidayCalc,
blurb: 'Statutory paid holiday in days or hours, pro-rated.',
intro: 'Calculate statutory minimum paid holiday for full-time, part-time and part-year workers, in days or hours.',
about: [
'UK workers are entitled to 5.6 weeks of paid holiday a year. For someone working five days a week that is 28 days, which is also the statutory cap — working six days a week does not raise the minimum above 28.',
'Part-time workers get the same 5.6 weeks, pro rata: three days a week gives 3 × 5.6 = 16.8 days. Someone who joins or leaves part-way through the holiday year gets a proportion of the full-year figure.',
'Workers with irregular hours, and part-year workers, accrue holiday at 12.07% of the hours they work instead (5.6 weeks ÷ 46.4 working weeks). This calculator covers fixed working patterns.'
],
faqs: [
{ q: 'How much holiday is a full-time employee entitled to?', a: '5.6 weeks a year. For a five-day week that is 28 days, which is the statutory maximum even for people who work more days.' },
{ q: 'How is holiday calculated for part-time workers?', a: 'Days worked per week × 5.6. Three days a week gives 16.8 days of paid holiday a year.' },
{ q: 'Are bank holidays included?', a: 'There is no statutory right to paid bank holidays on top of the 5.6 weeks. Employers can count them towards the minimum, and many contracts give more — check the contract.' },
{ q: 'How is holiday worked out for irregular hours?', a: 'Irregular-hours and part-year workers accrue 12.07% of the hours they work in each pay period.' }
]
},
{
id: 'salary', file: 'calc-take-home-pay.html', name: 'Take-Home Pay', icon: 'Wallet', Calc: SalaryCalc,
blurb: 'Salary after income tax, NI and pension.',
intro: 'See estimated take-home pay after income tax, employee National Insurance and pension, per year and per month.',
about: [
'Pension is deducted first, as a net pay arrangement. Income tax is then applied band by band to what remains above the personal allowance, and employee National Insurance is charged on gross pay.',
'The calculator uses 2025/26 rates for England and Northern Ireland: a £12,570 personal allowance that tapers away above £100,000, 20% to £50,270, 40% to £125,140 and 45% above. Employee NI is 8% between £12,570 and £50,270, then 2%.',
'Scotland sets its own income tax bands, so results for Scottish taxpayers will differ. Student loans and other deductions are not included.'
],
faqs: [
{ q: 'How is take-home pay calculated?', a: 'Gross salary minus pension contributions, income tax and employee National Insurance. Tax is charged band by band on pay above the personal allowance.' },
{ q: 'What personal allowance does the calculator use?', a: '£12,570, the 2025/26 figure. It reduces by £1 for every £2 of income above £100,000.' },
{ q: 'Does this work for Scotland?', a: 'No — Scotland has different income tax bands. National Insurance is the same across the UK.' },
{ q: 'Is pension taken before tax?', a: 'The calculator assumes a net pay arrangement, where pension contributions are deducted before income tax is worked out.' }
]
},
{
id: 'hourly', file: 'calc-hourly-rate.html', name: 'Hourly Rate', icon: 'Clock', Calc: HourlyCalc,
blurb: 'Convert an annual salary to an hourly rate.',
intro: 'Turn an annual salary into an hourly, daily and weekly rate, and check it against the National Living Wage.',
about: [
'The hourly rate is the annual salary divided by the hours paid across the year: contracted hours per week multiplied by paid weeks. Use 52 weeks when paid holiday is included in the salary.',
'The result is compared with the National Living Wage of £12.21 an hour for workers aged 21 and over, which applied from April 2025. Rates change every April, and lower rates apply to younger workers and apprentices.'
],
faqs: [
{ q: 'How do I convert a salary to an hourly rate?', a: 'Divide the annual salary by hours per week × paid weeks per year. £32,000 at 37.5 hours over 52 weeks is £16.41 an hour.' },
{ q: 'How many paid weeks should I use?', a: '52 if the salary includes paid holiday, which is usual for salaried staff.' },
{ q: 'Does the calculator check the minimum wage?', a: 'It compares the result with the April 2025 National Living Wage for workers aged 21 and over. Rates change each April, so confirm the current figure on GOV.UK.' }
]
},
{
id: 'notice', file: 'calc-notice-period.html', name: 'Notice Period', icon: 'CalendarClock', Calc: NoticeCalc,
blurb: 'Statutory minimum notice by length of service.',
intro: 'Find the statutory minimum notice an employer must give, based on an employee’s continuous service.',
about: [
'UK law sets a minimum notice period based on continuous service: none under one month, one week from one month to under two years, then one week for each complete year of service, up to twelve weeks.',
'An employee with at least a month’s service must give at least one week’s notice. Contracts often set longer notice, and the longer period applies. Statutory notice does not apply where someone is dismissed for gross misconduct.'
],
faqs: [
{ q: 'What is the statutory notice period in the UK?', a: 'One week after one month’s service, then one week per complete year once someone has two years’ service, capped at twelve weeks.' },
{ q: 'How much notice does an employee have to give?', a: 'At least one week once they have worked for a month, unless their contract says more.' },
{ q: 'Does the contract override statutory notice?', a: 'A contractual notice period applies if it is longer than the statutory minimum. It cannot be shorter.' },
{ q: 'Is notice required for gross misconduct?', a: 'No — statutory notice does not apply to a dismissal for gross misconduct.' }
]
},
{
id: 'cost', file: 'calc-employee-cost.html', name: 'Employee Cost', icon: 'Users', Calc: EmployeeCostCalc,
blurb: 'The true cost of an employee to your business.',
intro: 'Work out the full annual cost of an employee: salary plus employer National Insurance, pension and other costs.',
about: [
'An employee costs more than their salary. The employer also pays National Insurance — 15% on earnings above the £5,000 secondary threshold in 2025/26 — and pension contributions, with an auto-enrolment minimum of 3% of qualifying earnings above £6,240.',
'Add equipment, training, benefits and software licences to see the full figure. Eligible employers can claim the Employment Allowance, which reduces the employer NI bill; the calculator does not apply it.'
],
faqs: [
{ q: 'How much does an employee cost on top of salary?', a: 'Employer National Insurance, employer pension contributions and other costs such as equipment and training. The calculator shows the total and the uplift over salary.' },
{ q: 'What employer National Insurance rate is used?', a: '15% on earnings above the £5,000 secondary threshold, the 2025/26 rate.' },
{ q: 'What is the minimum employer pension contribution?', a: 'Under auto-enrolment, employers must contribute at least 3% of qualifying earnings.' },
{ q: 'Is the Employment Allowance included?', a: 'No. The result is the cost before any Employment Allowance, which eligible employers can use to reduce their NI bill.' }
]
},
{
id: 'overtime', file: 'calc-overtime.html', name: 'Overtime Pay', icon: 'Timer', Calc: OvertimeCalc,
blurb: 'Pay at time-and-a-half, double time and more.',
intro: 'Calculate overtime pay at standard rate, time-and-a-quarter, time-and-a-half or double time.',
about: [
'Overtime pay is the hourly rate multiplied by the overtime multiplier and the hours worked. At £14.50 an hour, six hours at time-and-a-half is £14.50 × 1.5 × 6 = £130.50.',
'There is no statutory right to a premium overtime rate in the UK — the rate depends on the contract. Average pay across all hours worked must not fall below the National Minimum Wage.'
],
faqs: [
{ q: 'How is overtime pay calculated?', a: 'Hourly rate × overtime multiplier × overtime hours.' },
{ q: 'What is time and a half?', a: '1.5 times the standard hourly rate. Double time is twice the standard rate.' },
{ q: 'Do employers have to pay extra for overtime?', a: 'Not by law. Premium rates depend on the contract, but average pay must stay at or above the National Minimum Wage.' }
]
},
{
id: 'payroll', file: 'calc-payroll-cost.html', name: 'Payroll Cost', icon: 'Banknote', Calc: PayrollCalc,
blurb: 'Annual and monthly payroll cost for a team.',
intro: 'Estimate the annual and monthly payroll cost of a whole team, including employer National Insurance and pension.',
about: [
'Each employee costs their salary, plus employer National Insurance at 15% above £5,000, plus employer pension on qualifying earnings above £6,240. The calculator applies those to an average salary across the team.',
'It is a planning estimate. Real payroll varies with individual salaries, tax codes, benefits and Employment Allowance eligibility.'
],
faqs: [
{ q: 'How do I estimate payroll cost?', a: 'Multiply headcount by average salary, then add employer National Insurance and pension contributions. The calculator does this for you.' },
{ q: 'Why use an average salary?', a: 'It gives a quick budget figure. NI and pension thresholds apply per person, so a team with very uneven salaries will differ from the estimate.' },
{ q: 'Does it include the Employment Allowance?', a: 'No. Eligible employers can reduce their NI bill with the Employment Allowance.' }
]
}
];
function CalcDisclaimer() {
return (
These calculators use 2025/26 UK rates for England and Northern Ireland and are provided for guidance only. They are not tax, legal or financial advice — check figures against HMRC guidance or your accountant before acting on them. Scotland operates different income tax bands.
);
}
function CalcCard({ c }) {
return (
{c.name} Calculator{c.blurb}
);
}
function CalculatorsBody() {
return (