How to Work Out Pro Rata Salary: Hourly, Weekly and Annual Pay Explained

Understanding Hourly, Weekly and Annual Pay

When you are offered a job or reviewing your current pay, you will often see figures expressed as an hourly rate, a weekly wage, or an annual salary. Each format has its uses, but to compare offers or calculate part-time pay you need to work out pro rata salary – that is, the proportional amount based on a full-time equivalent.

The Statutory Minimum Rates for 2026

The government sets legal minimum hourly rates that apply to almost all workers. From April 2026, the rates are:

• National Living Wage (aged 21 and over): £12.71 per hour
• National Minimum Wage (aged 18–20): £10.85 per hour
• National Minimum Wage (under 18): £8.00 per hour
• Apprentice rate: £8.00 per hour

These figures come from GOV.UK guidance and are the baseline for any salary calculation. If you are paid weekly or annually, you must still ensure your equivalent hourly rate meets these minimums.

How to Work Out Pro Rata Salary

Pro rata salary is most commonly used for part-time workers. The calculation is straightforward:

1. Find the full-time equivalent salary – this is the annual figure for a standard working week (often 35–40 hours).
2. Divide by full-time hours to get the hourly rate.
3. Multiply by your actual contracted hours and then by 52 weeks.

For example, if a full-time role pays £30,000 for 37.5 hours per week, and you work 20 hours, your pro rata salary is:

(20 ÷ 37.5) × £30,000 = £16,000 per year.

You can also work out pro rata salary from an hourly rate. If you know the hourly rate (say £12.71) and your weekly hours (25), your annual pro rata pay is:

£12.71 × 25 × 52 = £16,523.

This method is essential when comparing job offers or checking that your part-time pay is fair. For more detailed examples, see our pay guides.

Weekly vs Annual Pay: What the Data Shows

The Office for National Statistics (ONS) publishes the Annual Survey of Hours and Earnings. The latest data (April 2025) shows:

• Median weekly earnings for full-time employees: £766.60
• Median gross annual earnings for full-time employees: £39,039
• Median hourly earnings (excluding overtime) for full-time employees: £19.67

These figures are useful benchmarks. If you are offered a salary, you can compare it to the median to see where you stand. However, remember that many jobs pay above the minimum, especially in sectors like finance, IT, and healthcare.

Take-Home Pay vs Gross Pay

When you work out pro rata salary, you are calculating gross pay – the amount before deductions. Your take-home pay will be lower after tax, National Insurance, and pension contributions. The government’s Low Pay Commission notes that a full-time worker on the National Living Wage (35 hours per week) would see a 3.3% increase in weekly take-home income from April 2026.

Employers must also consider deductions that affect minimum wage compliance. The NHS Employers guidance explains that salary sacrifice arrangements (e.g., for childcare or a cycle to work scheme) can reduce the pay used for National Minimum Wage calculations. Even if your gross salary seems high, your equivalent hourly rate after deductions must still meet the statutory minimum.

Practical Tips for Job Seekers

• Always ask for the full-time equivalent salary when applying for part-time roles. This makes it easier to work out pro rata salary.
• Check your age band – the minimum wage increases at age 18 and again at 21.
• Use online calculators – many free tools can help you convert hourly, weekly, and annual figures.
• Remember overtime – if you work extra hours, your employer must pay at least the minimum wage for those hours too.

For more data on pay trends, visit our pay data page.

Common Mistakes to Avoid

• Assuming annual salary is for a 40-hour week – standard full-time hours vary by employer and sector. Always confirm the contracted hours.
• Forgetting to include unpaid breaks – your pay is based on actual working time, not the total time at work.
• Mixing gross and net figures – when comparing offers, use gross pay. Take-home pay depends on your personal tax code and deductions.

Summary

Understanding how to work out pro rata salary is a vital skill for UK workers. Whether you are moving from full-time to part-time, comparing job offers, or checking your pay against the legal minimum, the principles are the same: start with the full-time equivalent, apply the proportion of hours, and always verify against the current statutory rates. Use the official rates from GOV.UK and benchmark data from the ONS to make informed decisions.

For further reading, explore our topics section on part-time work and salary calculations.