Overtime Pay Calculator

The real hourly rate of a 50-hour week

Nobody works a 50-hour week at their headline rate. Take £15 an hour for 40 hours plus 10 overtime hours at time-and-a-half: the week pays (40 × 15) + (10 × 22.50) = £825, and £825 ÷ 50 hours = £16.50 an hour. That is your true rate — the number to compare against other jobs, not the £15 on the advert or the £22.50 on the overtime line.

The true rate is always between your base rate and your overtime rate, pulled toward whichever you work more of. Heavy overtime weeks look well paid per hour until you notice the base rate has not moved in three years and the overtime is doing all the work. If your true rate has barely risen while your hours have, you have had a workload increase disguised as stable pay.

It also reframes the “should I do overtime?” question. Ten hours at 1.5× lifts the true rate from £15 to £16.50 — a 10% uplift for 25% more hours. Whether that trade is worth it depends on the multiplier, which is why the next section matters.

• True hourly rate = total weekly pay ÷ total hours worked.
• 40 hrs at £15 + 10 hrs at 1.5× (£22.50) = £825 a week = £16.50 an hour true rate.
• The true rate sits between your base and overtime rates, weighted by hours.
• Compare jobs on true rate, not headline rate.

1.5× vs 1.25× vs flat: what multipliers mean

There is no statutory overtime multiplier in the UK — your rate is whatever your contract, collective agreement or employer policy says. Time-and-a-half (1.5×) is the most common premium in private-sector manual and shift work; 1.25× appears in retail and hospitality; double time (2×) is usually reserved for Sundays and bank holidays; and some employers pay overtime at the flat basic rate, which is legal as long as total pay clears the minimum wage.

The multiplier is worth more than it looks. Eight overtime hours a week at £15 an hour: at 1.5× that is £180 a week and £9,360 a year; at 1.25× it is £150 a week and £7,800 a year; at flat rate it is £120 a week and £6,240 a year. The gap between 1.5× and flat is £3,120 a year for identical hours — a full month's rent in much of the country, determined by one number in your contract.

When comparing employers, the multiplier often matters more than the base rate. A £14-an-hour job at 1.5× overtime pays £21 an overtime hour; a £15-an-hour job at flat rate pays £15. If you regularly work eight extra hours, the “lower-paid” job earns you £2,496 more a year.

• No legal minimum multiplier exists — it is contractual.
• 8 hrs/week at £15/hr: 1.5× = £9,360/yr; 1.25× = £7,800/yr; flat = £6,240/yr.
• The 1.5×-vs-flat gap is £3,120 a year for the same hours.
• A lower base rate with a better multiplier can beat a higher base rate with flat overtime.

Overtime vs a pay rise

Employers often offer extra hours instead of a raise, and employees often accept without pricing the alternative. The worked example gives you the exchange rate: £9,360 a year of overtime at 1.5× equals a £4.50-an-hour rise on a 40-hour basic week (£9,360 ÷ 2,080 hours). If the offered rise is £1 an hour — £2,080 a year — the overtime is worth four and a half times more in cash.

But the pay rise wins on every other dimension. A rise is pensionable at the higher rate, counts toward mortgage affordability, sick pay and redundancy calculations, and keeps paying when you are on holiday. Overtime pays only for hours actually worked, vanishes the moment hours dry up, and can be withdrawn unilaterally. Cash is not the whole comparison.

There is also a tax dimension. Overtime stacked on top of a salary near £50,270 can push the extra earnings into the 40% band, and overtime near £100,000 feeds the personal-allowance taper. A pay rise does the same, pound for pound — the tax treatment is identical — but overtime gives you the choice to stop, while a rise is permanent. Flexibility has value; price it.

• £9,360/yr of 1.5× overtime = a £4.50/hr rise on 40 basic hours.
• A rise counts toward pension, mortgage, sick pay and redundancy; overtime counts only when worked.
• Overtime can be cut without consultation; a rise cannot.
• Tax treatment is identical — but overtime lets you stop, a rise does not.

The tax angle: overtime can change your band

Overtime is taxed as ordinary earnings, which means it stacks on top of your salary and can tip you over thresholds. Someone on £46,000 basic doing £9,360 of annual overtime lands at £55,360 — and the £5,090 above £50,270 is taxed at 40% instead of 20%, costing an extra £1,018 versus the same overtime on a £40,000 salary. The calculator's annual total tells you which side of the line you are on.

National Insurance follows the same logic: 8% on the overtime up to £50,270 of total earnings, 2% above. And for graduates, student loan repayments take another 9% of the overtime above the plan threshold — on Plan 2, that is 9% of every overtime pound once total pay exceeds £29,385, which it almost always does.

None of this makes overtime a bad deal — even at 40% tax plus 2% NI plus 9% student loan, you keep 49p of every overtime pound at 1.5× rates. But the marginal keep-rate is the number to use when deciding whether the extra shift is worth your Saturday, not the headline multiplier.

Paid, unpaid and time off in lieu

You have no general legal right to be paid for overtime — it depends on your contract. Some contracts require overtime at set rates; some make it voluntary; some, particularly for salaried staff, include a clause saying the salary “covers all hours worked,” which is how unpaid overtime becomes contractual. Read the overtime clause before you assume.

Time off in lieu (TOIL) is the common alternative: an hour of overtime earns an hour (or more) of paid leave later. TOIL at 1:1 is worth less than paid overtime at 1.5× in cash terms, but it buys back time, which paid overtime never does. If burnout is the risk, TOIL is the better deal; if the mortgage is the priority, cash usually wins.

One hard limit applies regardless of contract: average weekly working time, including overtime, must not exceed 48 hours unless you have signed an opt-out. An employer cannot contractually require you to breach it, and you can withdraw an opt-out with notice. If your “voluntary” overtime is not actually voluntary, that is a conversation worth having.

• No automatic legal right to overtime pay — it is contractual.
• TOIL buys back time; paid overtime buys cash. Choose by what you are short of.
• The 48-hour average weekly limit includes overtime unless you opt out.
• “Salary covers all hours” clauses make unpaid overtime contractual — read yours.

What it covers, and what it does not

This calculator prices paid overtime for UK employees on hourly or salaried contracts. Enter your base hourly rate — for salaried staff, divide annual salary by 52 and then by contracted weekly hours — plus your weekly overtime hours and your multiplier, and it returns the overtime value per week, month and year alongside your true hourly rate.

It does not model unpaid overtime, TOIL accrual, or the 48-hour opt-out mechanics, which are contractual and scheduling matters. Tax figures use 2026/27 rates; for a full salary picture with overtime included, carry the annual overtime total into the take-home pay calculator.