How to Calculate Your Exact Age in the UK: Step-by-Step Guide

Introduction

Deadlines, notice periods, holiday allowances and ages all depend on counting days correctly. UK bank holidays make working-day counts trickier than they look.

This guide explains how to calculate your Exact Age in the UK, step by step. Work out your exact age in years, months and days, and when your next birthday is. You'll see the formula, a fully worked example and practical tips for UK readers.

What this calculation covers

Work out your exact age in years, months and days, and when your next birthday is.

Accurate date calculations help you meet legal deadlines, plan leave, and check notice periods or contract terms.

The method and formula

We count whole years, then whole months, then remaining days between your date of birth and the date you choose.

Every figure on our age Calculator follows this method, so you can check the working yourself.

Worked example

Here's a typical example using these figures:

Running them through the method gives:

The headline figure is age: 36 years, 3 months, 13 days. Change any input and the result will move with it.

How to use the calculator

1. Enter or choose date of birth.
2. Enter or choose age on.
3. Read your results. The main figure is shown at the top, with a breakdown underneath.
4. Try different values to compare scenarios side by side.

Tips for UK readers

• Check whether a deadline counts the start day, the end day or both.
• Bank holidays differ between England and Wales, Scotland and Northern Ireland.
• When a bank holiday falls on a weekend, a substitute day is usually given.
• Statutory holiday entitlement can include bank holidays.

Frequently asked questions

What's the quickest way to work out your Exact Age?

Use our free age Calculator. It applies this method automatically: We count whole years, then whole months, then remaining days between your date of birth and the date you choose.

Which bank holidays are included?

Working-day calculations use England and Wales bank holidays from 2025 to 2027.

Are start and end dates included?

Days-between counts the difference between dates; working-day counts include both start and end dates.

Is holiday entitlement including bank holidays?

The statutory 5.6 weeks can include bank holidays. Check your contract for how your employer handles them.

Summary

To work out your Exact Age, follow the method above: We count whole years, then whole months, then remaining days between your date of birth and the date you choose. For a quick, accurate answer with your own figures, use the calculator.

Next, read Your Exact Age: Common Mistakes, Tips and FAQs.