UK Pro Rata Salary Calculator - How Part-Time Hours Impact Salary and Benefits

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When applying for flexible working, it’s essential to understand the pro-rata salary impact working part-time or in a Job Share can have.

UK Pro Rata Salary Calculator - How Part-Time Hours Impact Salary and Benefits

When applying for flexible working, it’s essential to understand the pro-rata salary impact working part-time or in a Job Share can have.  When you work fewer days than full-time, your salary and holiday entitlement is adjusted downwards as well.  Additionally, your pension contributions will be less per year as both you and your employer provide a percentage based on your pro-rata salary.  It’s not all negative though, as you work fewer days, you will most likely have fewer expenses as you reduce things like travel or childcare costs.

Our UK Pro Rata Salary Calculator covers all of these elements and gives you the option to choose a quick basic version or a more involved advanced version that covers pension and expenses.

Further Reading: What Is Flexible Working?

What is Pro Rata

Pro rata refers to the proportional reduction in something based on the amount used, consumed or worked.  For example, pro rata in salary or benefits is about the decrease according to the reduced amount of hours worked.  Sometimes pro rata is used for things that are consumed, like when a trip is cancelled partway through, you may receive a pro rata refund based on the number of days you had left on the trip.

In general pro rata tends to be on a like for like basis, so things reduce consistently.  For example, if full time is 5 days and you work 4 days, you would expect to get 80% of the full-time salary, holiday, and benefit.  In the UK it is a requirement for salary and benefits to be proportional so you should not be asked to take a bigger pay cut than the hours or days you reduce.  If your employer does that, you can talk to citizens advice who have some guidance here.

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What to Think About When Moving from Full-Time to Part-Time or Job Share?

The idea of working flexibly and reducing your hours is appealing but you need to take into consideration the impact it has on your salary and benefits.

Pro-rata salary infographic
Pro-Rata Salary – What to Consider
  1. Salary – tends to be the single most significant factor that people take into consideration when thinking about working less time.  As you reduce your days, you will reduce your salary by the same proportion. For example, Jane works full-time on an annual wage of £35,000 and agrees on a Job Share with her employer, working three days a week.   Her new salary would be £21,000 as she now works 60% of the full-time role or ( 3 days / 5 days ) x 35,000).
  2. Holiday – the next most significant factor is holiday or vacation entitlement.  As you work fewer days or hours, you will receive fewer holidays on an annual basis. You should, in general, be able to take the same amount of holiday weeks off as before as each week you take requires less holiday as you work fewer days.  For example, John, with a full-time entitlement of 25 days (excluding bank holidays), moves to a four-day week part-time role.  He is now entitled to 20 days holiday but each week he takes off only requires four days holiday entitlement as this is his new weekly schedule.
  3. Pension – pensions are typically taken as a percentage of your salary so are impacted when you get paid less even if the proportion that you or your employer contribute stays the same. For example, when full-time Joanne has an annual salary of £48,000 and contributes 5% to her pension, which is £2,400 per year.  Joanne agrees to move to a Flexible Working contract with her employer on four days a week.  As her salary reduces to 80%, her pension contributions at 5% reduce down to £1,920.
  4. Expenses – when you work less time, you tend to have a reduction in your costs related to not working.  These can be considerable if you have high commuting costs and recently the first train network started supporting a three-day week season ticket.  Other expenses, like childcare and reduced meal bills, can be quite substantial.

UK Pro Rata Salary Calculator

How to use the UK pro rata salary calculator

  • Choose the basic calculator – if you are only interested in salary and holiday entitlement.
  • Choose the advanced calculator – if you are also interested in pension contributions and avoided expenses.
  • Input salary & benefits – provide your full-time weekly, monthly or annual salary, holiday entitlement and the percentage you contribute to your pension.
  • Flexible or part-time hours – move the slider down from five days to the new number of days you plan to work, this will calculate your reduced salary, holiday entitlement and pension.
  • Expenses when working – add any daily expenses you incur when you work like travel, childcare, etc.  This will then show the amount of expenses you will avoid each year as you move to a new pro rata flexible working contract.
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Frequently Asked Questions (FAQ)

How do I ask to reduce my hours?

The best way to reduce your hours at work is to submit a flexible working request. The UK has specific employment law that requires your employer to evaluate and seriously consider your request if you submit it in the correct way. This is called a statutory request. There are instances when making a non-statutory request is the best option. All instances are covered in depth in this article about Asking to Work Flexibly.

How many hours are full time in the UK?

There isn’t a specific number of hours that make a UK employee full-time but 35 hours is commonly seen as full-time at many employers. Check your contract of employment as the number of hours you work in a full-time position can be different, and this will impact the pro rata value of your salary and benefits if you are thinking of switching to part-time.

What’s the difference between pro rata and per annum?

Pro rata and per annum are different. Pro rata refers to the proportional reduction in something based on the amount used, consumed or worked, e.g. the reduction in your salary when you work 20% fewer hours. Per annum, on the other hand, refers to the time frame of each year, e.g. 25 days holiday per annum refers to the number of holidays you receive per year. Pro rata and per annum are often used together, such as describing the annual change in someone’s salary when working fewer days.

What happens if your working day falls on a bank holiday?

You are entitled to the same number of bank holidays as anyone else but on a pro rata basis. Employers usually handle this by adding the bank holiday entitlement to your annual holiday and working out what the total holiday you should receive is. If any of your days do fall on a bank holiday, you must take it from one of your days holiday.

In summary

Understanding pro rate salary when you think about moving to a flexible working contract is a super important part of the decision.  Part-time hours reduce your salary, holiday, and pension contribution on a pro rata basis.

If you are not planning to reduce the amount you work, our guide to flexible hours can help you think through what option you have.

If you are thinking of moving from full-time to part-time, discuss with your employer how or if your job can be redesigned to account for the reduced time.  Performing a full-time job on a part-time salary is one of the top reasons people choose Job Shares as the role is staffed full-time by two part-time people.

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