Your pro rata salary
£18,000a year
A month
£1,500.00
A week
£346.15
That is 60% of the full-time salary. After tax and National Insurance: £16,479.60 a year, £1,373.30 a month.
Part-time hours on a £30,000 full-time salary
| Hours a week | Share | A year | A month | Take-home a month |
|---|---|---|---|---|
| 15 | 40% | £12,000 | £1,000.00 | £1,000.00 |
| 20 | 53.3% | £16,000 | £1,333.33 | £1,253.30 |
| 22.5 | 60% | £18,000 | £1,500.00 | £1,373.30 |
| 25 | 66.7% | £20,000 | £1,666.67 | £1,493.30 |
| 30 | 80% | £24,000 | £2,000.00 | £1,733.30 |
Full-time week of 37.5 hours, 52 weeks, England, Wales and Northern Ireland, tax code 1257L.
Quick answers
How do I work out a pro rata salary?
Full-time salary × your hours ÷ full-time hours. £30,000 × 22.5 ÷ 37.5 = £18,000. If you also work fewer weeks, multiply by your weeks ÷ 52.
Is pro rata pay taxed differently?
No. Tax and National Insurance are worked out on what you actually earn, so a lower salary means a lower tax bill: £18,000 leaves £16,479.60 after both.
Does pro rata holiday work the same way?
Yes. Statutory holiday is 5.6 weeks a year for everyone; part-time workers get the same 5.6 weeks of their own working pattern. The holiday pay calculator works it out in days.
Tax and National Insurance: GOV.UK and HMRC rates for 2026/27. Checked 31 Oct 2026.