Pro-Rata Salary Calculator

Part-time jobs are often advertised with full-time salaries. Use our pro-rata salary calculator to work out what your actual pay will be, if you do a part-time job. Simply change the number in the “Pro-rata Weekly Hours” field below to what your weekly hours are, type in the annual full-time salary (on the left), then hit the “calculate” button. The figures are based on the 2017/18 tax year, which started on Thursday 6th April 2017. The 16/17 net salary figures are also shown when you enter a salary, so you can do a year on year comparison.


Age Group



Yearly Monthly Weekly Daily*
Gross Income £0.00 £0.00 £0.00 £0.00
Taxable Income £0.00 £0.00 £0.00 £0.00
Tax £0.00 £0.00 £0.00 £0.00
National Insurance £0.00 £0.00 £0.00 £0.00
Student Loan £0.00 £0.00 £0.00 £0.00
Take Home £0.00 £0.00 £0.00 £0.00
4 Weekly Pay £0.00 £0.00 £0.00 £0.00

*Daily values based on a 5-day working week

How to use the pro-rata salary calculator

Enter the full-time annual salary into the “full-time” salary field. Then enter the “pro-rata” number of weekly hours into the “Pro-rata Weekly Hours” field.

The “Normal Weekly Hours” field has a default figure of 37.5, but you can amend this if you wish to. “Pro rata” means “proportional” in latin.

If you want to know how to work out the pro rata salary yourself, then there are three options:

i) Using the number of hours worked in a week. If the normal weekly hours are 37.5 (check with your employer), and you will do 15 hours a week, that is 40% of a full week (because 15 divided by 37.5 is 40%). If the full time salary is £30k, multiply 40% by £30k, which will give you £12k.

ii) Using the number of days work in a week – if you’re doing 2 days a week, that is also 40% of a full week (2 divided by 5 = 0.4). Multiply 0.4 or 40% by the full-time salary (£30k), which gives you £12k.

iii) Using a combination of the weekly wage and hourly pay to work out the pro rata annual salary.

a) Work out the weekly wage – if the annual salary is £52,000; divide it by 52 (the number of weeks in a year) to get the weekly salary – in this case £1,000 a week.

b) Work out the hourly pay – if a full working week is 37.5 hours a week, then didvide the weekly wage by 37.5 to get the hourly wage ie £1,000 divide by 37.5 = £26.67 (rounded to two decimal places) per hour.

c) Use these and the hours worked to work out the pro rata weekly wage – eg if the number of hours worked per week is ten, then multiply ten by £26.67 to get the pro rata weekly wage – this is £266.70 in this example.

d) Use the pro rata weekly wage to work out the pro rata annual salary – in this case we’d multiply the pro rata weekly wage by number of weeks that the part time employee works in a given year. If they work for 45 weeks in a year, then we multiply £266.70 by 45 to get an annual pro rata salary of £12,000.

However, our calculator gives you a breakdown of the gross and net (after-tax) figures for the pro rata salary on a yearly, monthly and weekly basis in seconds, as well as the national insurance contributions. This would take you much longer to work out if you were to do it out yourself. We’re here to save you time!

Advanced options (click the “Show/Hide advanced options for these):

If you pay into a pension, you can enter the monthly percentage amount of your salary that you pay into the “Pension Contributions:” field.

If you do overtime fill in either the “Monthly overtime (1.5x)” field or the “Monthly overtime (2x)” field. The 1.5x field works out your hourly rate when it’s multiplied by one and a half times. The 2x field doubles the hourly rate, as some people get paid double the rate when working overtime.

If you know your tax code, you can enter it in the “Any Tax Code” field to get a more accurate view of your net salary.

If you receive Childcare vouchers, then enter the monthly value of the vouchers you receive in the “Child Care Vouchers:(Monthly)” field.

The calculations are all based on data for the 2015/2016 tax year (income tax, national insurance and student loan information) which began in April 2015.

If you wish to see figures from previous tax years, simply click on the drop-down menu next to the word “Year” at the top of the calculator.

A more detailed explanation of how the tax rules work can be found here:

Disclaimer: Information provided on this site is for illustrative purposes only.Do not make any major financial decisions without consulting a qualified specialist. We also ask that you take a moment to read our Terms and Conditions and Privacy Policies.