18 calculators

Calculators

Date and time questions that are fiddly to do in your head, plus the UK work ones: how much holiday you are owed, and when the bank holidays fall. Pick one and get an answer straight away.

Dates and time

Days between dates

Count the days between any two dates, split into weeks, months, working days and weekend days.

1 Jan → 31 Jan = 30 days

Age calculator

Exact age in years, months and days from a date of birth, plus the countdown to the next birthday.

Born 15 Mar 1990 = 36y 3m

Working days calculator

Count working days between dates, or add them to one. Skips weekends and UK bank holidays.

All of Jan 2026 = 22 working days

Add or subtract days

Add days to a date or count back from one, in calendar days or working days.

10 Jul + 90 days = 8 Oct

Countdown to a date

Days until a birthday, deadline or any date you name, with a live clock. Shareable by link.

Live countdown, share the link

Time duration calculator

How long between two times, including overnight, with an optional unpaid break taken off.

09:00 → 17:30 = 8h 30m

Work and holiday (UK)

Holiday entitlement calculator

The UK statutory minimum holiday for your working pattern, pro rata if you start part way through the year.

3 days a week = 16.8 days

UK bank holidays, and how to make them last

Every UK bank holiday, and where to put your leave so a few days turn into a fortnight.

Take 4, get 16 days off

Notice period calculator

Statutory minimum notice from your start date, for either side. They are not the same.

10 years in: 10 weeks vs 1

Overtime calculator

Overtime pay at any multiplier, with the average hourly rate the minimum wage is measured against.

8 hrs at 1.5× £15 = £180

Statutory sick pay calculator

Statutory Sick Pay under the new April 2026 rules: no waiting days, no earnings floor.

5 days off = £123.25

Maternity pay calculator

Statutory Maternity Pay across all 52 weeks of leave, including the weeks that pay nothing.

£600/wk → £540, then £194.32

Pro rata salary calculator

What a full-time salary comes to for the days or hours you actually work.

£30k, 3 days a week = £18,000

Numbers and money

Dividend tax calculator

Dividend tax at the 2026/27 rates, stacked on top of your salary, with the band breakdown.

£30k + £10k div = £1,021.25

Fuel cost calculator

Fuel cost for any journey, split between passengers, with cost per mile.

100 miles at 45mpg = £15.20

VAT calculator UK

Add VAT to a price or work backwards from a total. Net, VAT and gross, every time.

£100 inc VAT = £83.33 + £16.67

Discount calculator

What you pay after a discount, what percentage a sale is, and what to charge with a markup.

£80 less 30% = £56

Average calculator

Mean, median, mode, range and standard deviation from a list of numbers.

Paste from a spreadsheet

Which one do I need?

How long is it from one date to another?Days between dates
How old is someone, exactly?Age calculator
How many working days, ignoring weekends and bank holidays?Working days calculator
What date is 30 days from now? Or 60 days before?Add or subtract days
How long until my birthday, or a deadline?Countdown to a date
How many hours between two times, or across a night shift?Time duration calculator
How much holiday am I legally owed?Holiday entitlement calculator
When are the bank holidays, and how do I make them last?UK bank holidays, and how to make them last
How much notice do I have to give, or am I owed?Notice period calculator
What are my overtime hours worth?Overtime calculator
How much sick pay am I owed, and from which day?Statutory sick pay calculator
How much maternity pay will I actually get, and for how long?Maternity pay calculator
How much tax will I pay on my dividends?Dividend tax calculator
What will the petrol cost, and what do I owe for a lift?Fuel cost calculator
What is this plus VAT? Or what was it before VAT?VAT calculator UK
What do I pay with 30% off? Or what should I charge?Discount calculator
What is the average of these numbers? Or the median, or the mode?Average calculator
The advert says pro rata. What would I actually be paid?Pro rata salary calculator

What these have in common

Every one runs in your browser. Nothing you type is sent to a server, there is no sign-up, and there is nothing to install. Open a page, get the answer, close the tab.

The maths runs in UTC on whole calendar days, which is the reason a clock change never quietly adds or drops a day. Years and months are counted as real calendar units rather than fixed blocks of 30 or 365 days, so an answer of “3 months” means three actual months. Leap years, including birthdays on 29 February, come out right.

Where a tool leans on outside data it says so. The working days calculator uses the official gov.uk bank holidays feed, with England & Wales, Scotland and Northern Ireland handled separately, because their holidays genuinely differ. Full detail is on how we build these.

A note on counting days

Most arguments about date maths come down to one question: does the last day count? Booking a hotel from the 1st to the 5th is four nights but touches five days. Both numbers are right, they just answer different questions.

So the tools are explicit about it. The days between dates calculator has an include the end date tick box, and tells you which way it counted, rather than picking one and leaving you to guess.

Common questions

Are these calculators free?

Yes. All of them, with no account and no limit on how often you use them.

Do they work on a phone?

Yes. The pages are light and work on any modern browser, on any device.

Do the calculators handle leap years?

Yes. Day counts are exact rather than estimated, so leap years and 29 February birthdays are counted against the real calendar.

Do they take bank holidays into account?

The working days calculator does, if you choose a UK region. The others count weekends only, because holidays vary by country and plenty of contracts define their own list.