What does pro rata mean UK?

Pro rata is a Latin term meaning "in proportion." In UK employment, it means that a part-time worker receives the same hourly rate as a full-time employee, with their total pay calculated proportionally to the hours they work. It is a legal requirement under the Part-time Workers Regulations 2000.

Is pro rata before or after tax?

Pro rata salary is always quoted gross, before income tax and National Insurance deductions. Your actual take-home pay will be lower. The personal allowance for 2026/27 is £12,570, meaning you pay no income tax on earnings below this threshold.

How many days holiday do I get pro rata?

UK workers are entitled to 5.6 weeks of paid holiday per year under the Working Time Regulations 1998. For a part-time worker doing 3 days per week, this is 5.6 × 3 = 16.8 days. For 4 days per week it is 22.4 days.

Can I be paid less than minimum wage on a pro rata basis?

No. The national living wage for 2026/27 is £12.71 per hour for workers aged 21 and over, as set by HMRC. Your pro rata salary must result in an effective hourly rate at or above the applicable minimum wage rate for your age group.

What is a pro rata salary calculator?

A pro rata salary calculator is a tool that works out the proportional salary for a part-time worker based on a full-time equivalent salary and hours. You enter the full-time salary, full-time hours per week, and your actual hours, and the calculator applies the standard UK formula (full-time salary ÷ full-time hours × actual hours) to give your pro rata annual, monthly, weekly and daily figures instantly.

Updated 6 April 2026

Pro Rata Calculator · Free UK 2026/27

Calculate your pro rata salary instantly, use as a pro rata calculator or pro rata salary calculator. Updated with HMRC 2026/27 rates.

✓ Free to use✓ Updated 2026/27✓ HMRC aligned✓ Instant results

Pro Rata Calculator

Enter your details below. Your result updates instantly

Full-time equivalent salary

£/ year

Full-time hours per week(standard for this role)

hrs / wk

Your actual hours per week

hrs / wk

Pro Rata Annual Salary

£—

Enter your figures above to calculate

Monthly

£—

Weekly

£—

Daily

£—

Hourly

£—

All figures are gross, before income tax and National Insurance. Results are for guidance only. See also our Holiday Pay Calculator.

How to Calculate Pro Rata Salary

Quick Answer: To calculate pro rata salary, divide the full-time annual salary by the full-time hours per week, then multiply by the actual hours worked. A £30,000 salary for a 37.5-hour week, worked at 25 hours, gives a pro rata salary of £20,000. This figure is always gross, before tax and National Insurance.

What is Pro Rata?

Pro rata is a Latin term meaning “in proportion.” In UK employment, it means a part-time worker receives the same hourly rate as their full-time equivalent, with total pay calculated proportionally. Under the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000, employers must not treat part-time workers less favourably than comparable full-time workers. This pro rata salary calculator applies the standard HMRC-aligned formula and gives you annual, monthly, weekly and daily figures in one step.

Formula

Pro Rata Salary = (Full-time salary ÷ Full-time hours per week) × Actual hours per week

e.g. (£30,000 ÷ 37.5) × 25 = £20,000

Worked Example

Full-time salary£35,000

Full-time hours (÷ 37.5)÷ 37.5

Hourly rate (annual)£933.33

× Actual hours (28 hrs/wk)× 28

Pro rata annual salary£26,133

Pro rata monthly (÷ 12)£2,178

All figures are gross (before tax and National Insurance).

Pro Rata Holiday Entitlement

Part-time workers are entitled to 5.6 weeks of paid holiday per year under the Working Time Regulations 1998, calculated pro rata to the days they work. A worker doing 3 days per week receives 5.6 × 3 = 16.8 days. According to GOV.UK, holiday pay must be based on average weekly earnings, not a lower base rate.

Key UK rates for pro rata calculations 2026/27

Personal allowance	£12,570
National Living Wage (21+)	£12.71/hr
Statutory holiday	5.6 weeks
Working weeks per year	52

Source: HMRC / GOV.UK, 2026/27 tax year

Frequently Asked Questions

Divide your full-time annual salary by the full-time hours per week, then multiply by your actual hours per week. For example, a £30,000 salary for a 37.5-hour week, worked at 25 hours, gives £20,000 pro rata. This is always a gross figure before tax and National Insurance.