Reviewed for UK readers: September 2026.
A straightforward salaried-role estimate converts the full-time annual salary into an hourly equivalent using the full-time weekly hours and the number of paid weeks in the salary year. Our pro rata wage calculator can then apply that full-time rate to a reduced weekly schedule.
Be careful with term-time jobs and hourly-paid contracts: their paid weeks and holiday-pay treatment can differ, so the simple 52-week salary conversion may not be the contractual payroll method.
Quick answer
- Basic salary hourly equivalent = annual salary ÷ (weekly hours × 52) for a full-year salaried estimate.
- Part-time salary = same equivalent rate × part-time weekly hours × 52.
- The underlying equivalent rate should not fall just because hours reduce.
- Term-time and irregular-hour contracts can need different paid-week assumptions.
Example using 37.5 hours
£39,000 ÷ (37.5 × 52) = £20 per hour as a simple full-year salary equivalent. A 22.5-hour contract at the same equivalent rate gives £20 × 22.5 × 52 = £23,400 annual pro rata salary, which is 0.6 FTE.
Example using 40 hours
£41,600 ÷ (40 × 52) = £20 per hour. A 32-hour week gives £33,280 annual salary, or 0.8 of the full-time annual rate.
Why payroll hourly rates can differ
Some employers use 52.143 weeks, annual working hours, paid hours after unpaid breaks or collective-agreement conventions. The “salary ÷ 52 weeks” method is therefore a useful estimate, not a universal payroll rule.
Part-time equality
Part-time workers should not be treated less favourably simply because they work part time. Where roles are otherwise equivalent, comparing full-time and part-time hourly-equivalent rates is a useful way to spot an apparent mismatch that should be queried.
Overtime
Part-time employees do not necessarily receive an overtime premium as soon as they exceed their own contracted hours. GOV.UK notes that overtime treatment can depend on whether they exceed the normal full-time hours and on the contract.
Common pro rata salary mistakes
The most common errors are using the wrong full-time comparator, treating unequal days as equal, confusing gross and net salary, and applying a term-time reduction to a role that is already quoted as an actual salary. Always identify the full-time salary, full-time hours and your contracted hours before calculating.
If the employer provides an official FTE percentage, use it as a cross-check. Small differences can come from rounding; larger differences usually mean another factor such as paid weeks or an allowance is involved.
Use the calculator
For a quick gross salary estimate, use the Pro Rata Calculator UK. Enter the full-time salary and your hours, days or FTE, then compare the result with your contract or payroll figure.
Frequently asked questions
How do I find hourly pay from annual salary?
For a simple full-year estimate, divide annual salary by weekly full-time hours multiplied by 52.
Does part-time work reduce the hourly rate?
A normal pro rata salary reduction changes total hours and total salary, not the equivalent base rate for the same role.
Should I use 52 or 52.143 weeks?
Use the employer’s payroll convention when known. 52 is a simple estimator; some payroll systems use a more precise annualisation factor.
Is overtime automatically paid after my part-time hours?
Not necessarily. Contract terms and the full-time comparator can affect when an overtime premium applies.
Authoritative sources
This article is general information, not personalised legal, tax or payroll advice. Employment contracts, collective agreements and individual circumstances can change the correct result.
Important: This article is general information, not personalised financial, tax, payroll, employment or legal advice. Check important figures against your contract and current official guidance.