Thirty hours a week sits in a sweet spot for many UK workers: close enough to full-time to keep a substantial income, but with a day or a few shorter days free each week. It is a common pattern for parents, for people easing back from full-time work, and for anyone on a four-day week of 7.5-hour days. But as with any part-time pattern, the payslip figure is not the headline salary — it is a pro rata share of it. This guide explains how a pro rata salary calculator for 30 hours a week works, with worked examples you can check against your own contract.
For the instant answer, use the free pro rata salary calculator on our homepage: enter the full-time salary, your 30 hours, and the employer’s full-time week, and it returns your annual, monthly, and hourly pro rata pay. The maths below shows exactly how it gets there.
The pro rata formula for 30 hours a week
Pro rata salary = full-time salary × (your weekly hours ÷ full-time weekly hours)
On a 37.5-hour full-time week, 30 hours is 30 ÷ 37.5 = 0.80, or 80% FTE. On a 40-hour week, 30 hours is 30 ÷ 40 = 0.75, or 75% FTE. That single difference — the employer’s definition of full-time — is the most important number in the whole calculation, and it is stated in your contract. A four-day week of 7.5-hour days is exactly 30 hours, which is why 80% FTE is so often quoted for four-day-week roles; but a four-day week of 8-hour days is 32 hours, not 30, and would be calculated differently.
Worked example 1: £32,000 FTE on a 37.5-hour week
| Figure | Calculation | Result |
|---|---|---|
| FTE fraction | 30 ÷ 37.5 | 80% |
| Pro rata annual salary | £32,000 × 0.80 | £25,600 |
| Pro rata monthly pay (gross) | £25,600 ÷ 12 | £2,133.33 |
| Hourly rate | £32,000 ÷ (37.5 × 52) | £16.41 per hour |
| Weekly pay (gross) | £16.41 × 30 | £492.31 |
As with every pro rata calculation, the hourly rate is the same as for a full-time colleague in the same role. Part-time status changes the number of hours paid, never the rate per hour. If a comparison with a full-time colleague shows a different hourly rate, that discrepancy is the first thing to query.
Worked example 2: the same salary on a 40-hour week
| Figure | Calculation | Result |
|---|---|---|
| FTE fraction | 30 ÷ 40 | 75% |
| Pro rata annual salary | £32,000 × 0.75 | £24,000 |
| Pro rata monthly pay (gross) | £32,000 × 0.75 ÷ 12 | £2,000 |
| Hourly rate | £32,000 ÷ (40 × 52) | £15.38 per hour |
The same £32,000 headline salary produces £1,600 a year less on a 40-hour week than on a 37.5-hour week. When comparing two 30-hour jobs, the headline salary tells you almost nothing on its own — the hourly rate, or the pro rata annual figure calculated on each employer’s own full-time week, is the honest comparison.
Pro rata pay at common UK salaries (30 hours a week)
| Full-time salary | 37.5-hour week (80% FTE) | 40-hour week (75% FTE) |
|---|---|---|
| £25,000 | £20,000 | £18,750 |
| £28,000 | £22,400 | £21,000 |
| £32,000 | £25,600 | £24,000 |
| £36,000 | £28,800 | £27,000 |
| £42,000 | £33,600 | £31,500 |
| £50,000 | £40,000 | £37,500 |
All figures are gross, before income tax, National Insurance, and pension contributions. Your take-home pay will be lower, and the exact amount depends on your tax code, pension scheme, and any student loan or salary-sacrifice arrangements.
Holiday entitlement for 30 hours a week
Holiday scales in the same proportion. The statutory minimum of 5.6 weeks for a full-time worker becomes 5.6 × 30 = 168 hours a year for a 30-hour worker. Where full-time staff receive 25 days of annual leave plus 8 bank holidays (33 days), the hours equivalent on a 7.5-hour day is 247.5 hours, and a 30-hour worker’s share is 0.80 × 247.5 = 198 hours.
Calculating holiday in hours matters most when your pattern is not five equal days. A worker doing four 7.5-hour days who is given holiday as “20 days” on a five-day basis would need those days converted properly: 20 days of a full-timer’s leave is not the same as 20 of your working days. Ask payroll to state your entitlement in hours, and check that bank holidays falling on your non-working days are handled fairly — many employers give part-time staff a pro rata bank-holiday allowance in hours rather than giving time off only when a bank holiday lands on a working day.
What to check on your payslip
Salaried part-time staff are normally paid in twelve equal monthly instalments, so in the first example the gross monthly pay should be £2,133.33 every month. Deductions then follow: PAYE income tax on earnings above the personal allowance, employee National Insurance, and pension contributions. Because the pro rata salary of £25,600 is below the higher-rate income tax threshold, tax is charged at the basic rate on the taxable portion, but your tax code and any benefits in kind can change the figure.
If your monthly gross pay does not equal your annual pro rata salary divided by 12, raise it with payroll first — a surprising number of payslip errors are simple fraction errors, such as using 30 ÷ 35 instead of 30 ÷ 37.5, or applying a five-day fraction to a four-day pattern.
The four-day week question
Thirty hours is often described as “a four-day week”, but the two are not automatically the same. A four-day week can mean four 7.5-hour days (30 hours, 80% FTE on a 37.5-hour week), four 8-hour days (32 hours, 85.3% FTE on a 37.5-hour week, or 80% on a 40-hour week), or even four longer days with the same pay as five — the “100:80:100” model, where you work 80% of the time for 100% of the pay. That last model is not pro rata at all: it is a compressed or reduced-hours arrangement with full pay, and it must be stated explicitly in the contract. Never assume a four-day-week advert means full pay unless it says so; most four-day roles are pro rata at the hours actually worked.
Overtime and extra hours
One of the most misunderstood points for 30-hour workers is overtime. In many contracts, overtime rates only apply above the full-time weekly hours (37.5 or 40), not above your contracted 30 hours. Hours between 30 and 37.5 may be paid at your normal hourly rate — these are sometimes called “additional hours” rather than overtime. Other employers pay overtime above your contracted hours. The difference can be worth hundreds of pounds a year if you regularly cover extra shifts, so read the overtime clause before you agree to a pattern, not after.
Benefits, pension, and bonuses
Most contractual benefits scale pro rata: pension contributions are usually a percentage of actual pay, so they fall in line with hours; annual bonuses expressed as a percentage of salary are calculated on pro rata salary; and allowances such as a car allowance may be pro rata or full depending on the contract wording. Some benefits do not scale: a season-ticket loan, private medical cover, or a fixed training budget may be available in full regardless of hours. The Part-time Workers Regulations protect you against less favourable treatment overall, but they allow pro rata scaling of pay and most monetary benefits — the protection is against being treated worse than the pro rata proportion, not against scaling itself.
Other working patterns: 20 hours a week · 24 hours a week · 37.5-hour week · 40-hour week · 2 days a week · 3 days a week · 4 days a week · 37.5 vs 40 hours · part-time hours tables · pro rata hours · days vs hours · examples by days per week
Frequently asked questions
Is 30 hours a week part-time or full-time? It is part-time if full-time at your employer is more than 30 hours, which it is in almost every UK workplace. The label matters less than the fraction: 30 hours is 80% of a 37.5-hour week and 75% of a 40-hour week.
Can my employer cut my hours from 37.5 to 30 without cutting my pay? Only if you agree to a contract change that says so. Normally a reduction in hours brings a pro rata reduction in pay, unless the change is a formal flexible-working arrangement with protected pay or a four-day-week trial on full pay.
Does working 30 hours affect my state pension? State pension qualifying years depend on National Insurance contributions, not hours. As long as your earnings are above the lower earnings limit in a tax year, you build a qualifying year, so a 30-hour week on a normal salary still counts in full.
Working out your own figure in under a minute
If you have your contract to hand, the whole check takes less than a minute: find the full-time salary, find the employer’s full-time weekly hours, divide your 30 hours by that figure, and multiply the salary by the result. For example, a £28,000 salary on a 37.5-hour week gives £28,000 × 0.80 = £22,400 a year, or £1,866.67 a month before deductions. If your payslip shows a different gross monthly figure, the gap is either a different full-time week, a salary-sacrifice arrangement such as pension or cycle-to-work deductions taken before the headline figure, or an error worth querying with payroll.
The bottom line
Pro rata pay for 30 hours a week is 80% of the full-time salary on a 37.5-hour week, or 75% on a 40-hour week. On a £32,000 FTE salary, that is £25,600 or £24,000 a year respectively, before deductions, with holiday of 168 statutory hours a year. Confirm your employer’s full-time week, check that your hourly rate matches full-time colleagues, get holiday stated in hours, and clarify the overtime threshold before you sign. With those four checks done, a 30-hour pattern is one of the most straightforward part-time arrangements to verify — and one of the easiest to get right.