Understanding Pro Rata Salary

When comparing hourly jobs with salaried offers, one of the most common questions is how to work out pro rata salary. Pro rata simply means 'in proportion' – it is the method used to calculate the equivalent annual salary for a part-time role based on the full-time rate. Whether you are considering a part-time position, a job share, or moving from an hourly contract to a salaried role, understanding pro rata calculations helps you make fair comparisons.

What Is Pro Rata?

A pro rata salary is the amount a part-time employee would earn if they worked the full-time hours. Employers often advertise salaries as 'full-time equivalent' (FTE) and then adjust for the actual hours worked. For example, if a full-time role pays £30,000 per year for a 37.5-hour week, someone working 20 hours per week would receive £30,000 × (20 ÷ 37.5) = £16,000. This ensures part-time workers are paid equitably.

How to Work Out Pro Rata Salary from an Hourly Rate

If you know your hourly rate, you can calculate the full-time equivalent annual salary and then scale it down for part-time hours. The basic formula is:

Annual salary = hourly rate × hours per week × 52 weeks

For a full-time employee on a 37.5-hour week (common in the NHS and many public sector roles), an hourly rate of £20.02 gives an annual salary of £20.02 × 37.5 × 52 = £39,039 – matching the UK median full-time annual earnings reported by the ONS ASHE for April 2025.

For part-time work, simply replace the full-time hours with your contracted hours. For instance, at £15 per hour for 25 hours per week: £15 × 25 × 52 = £19,500 per year. This is your pro rata annual salary.

UK Benchmarks: ONS and NHS Pay Scales

The Office for National Statistics (ONS) Annual Survey of Hours and Earnings (ASHE) provides authoritative data. In April 2025, median gross annual earnings for full-time employees were £39,039, and median hourly earnings (excluding overtime) were £19.67. The National Living Wage for employees aged 21 and over was £12.21 per hour, rising to £12.71 in 2026/27 (as per the on-site reference database).

For NHS staff, the Agenda for Change pay scales for 2026/27 show hourly rates ranging from £12.92 (Band 2) to £66.37 (Band 9) in England, Wales and Northern Ireland, based on a 37.5-hour week. Band 5 (newly qualified nurses, for example) starts at £16.40 per hour, while Band 6 starts at £20.44. These rates are useful benchmarks when comparing hourly jobs with salaried offers.

Comparing Hourly Jobs with Salaried Offers

Hourly jobs often include additional payments that salaried roles may not. For example, NHS staff can receive:

• Unsocial hours enhancements: weekday nights and Saturdays attract +30% to +47% (depending on band); Sundays and public holidays +60% to +94%.
• London weighting (HCAS): Inner London receives 20% of basic salary (minimum £5,794, maximum £8,746); Outer London 15% (min £4,870, max £6,137); Fringe areas 5% (min £1,346, max £2,270).

When comparing a salaried offer with an hourly role, you should factor in these extras. A salaried position may offer stability and benefits (pension, holiday pay) but might not pay overtime. Use our Hourly to Salary tool to convert your hourly rate into an annual figure, and consider the total compensation package.

Using the Hourly to Salary Calculator

Our hourly calculator lets you quickly convert hourly rates to annual, monthly, and weekly figures. Simply enter your hourly rate and your typical weekly hours (including any regular overtime). The calculator assumes a 52-week year and no unpaid breaks. For part-time workers, it automatically shows the pro rata salary.

Key Caveats

• Hours assumption: The standard full-time week varies. NHS uses 37.5 hours; many office roles use 35 or 40 hours. Always check your contract.
• Overtime and bonuses: Hourly-to-annual conversions assume a steady contracted week. Actual earnings may be higher if you regularly work overtime or receive bonuses.
• Holiday pay: Some hourly workers receive holiday pay as an additional 12.07% of earnings (for irregular hours). This is not included in basic rate conversions.
• Tax and National Insurance: The figures above are gross. Your take-home pay depends on tax code, pension contributions, and student loan repayments.

Summary

Knowing how to work out pro rata salary is essential for comparing job offers. Use the formula: hourly rate × weekly hours × 52. For part-time roles, use your actual hours. Cross-check with UK benchmarks like the ONS median of £39,039 or NHS pay bands. Remember to account for London weighting, overtime, and unsocial hours when evaluating hourly versus salaried positions. For more guidance, explore our salary articles and salary data.