12 online finance calculators everyone should bookmark

2 min Read Published: 09 Aug 2013
The best financial calculators on the internet

During the years of working in finance and writing this site I've come across some absolute gems of finance calculators. While one or two are mainstream the best are often difficult to find even when using the best search engines. So here I list 12 of the most useful financial calculators, by category, that I've found on the internet. If you have come across any others which you think should be included on the list feel free to share them by leaving a comment at the foot of the page.

Income tax

This PAYE tax calculator can quickly be used to make sure you are paying the correct amount of tax under. Brilliantly simple to use

Capital Gains Tax (CGT)

This CGT calculator will work out whether you have a CGT liability, and if there is a liability, the amount of the liability.

Benefits and Tax Credits Calculator

Quickly find out which benefits you are entitled to and how much you can claim with the official benefits calculator


This first mortgage calculator can be used to:

  • work out your monthly repayments for a given mortgage both on a repayment and an interest only basis.
  • show the impact of a mortgage rate (or indeed an interest rate) change on the amount  of your monthly payments.

My second mortgage calculator pick can be used to show how much is still outstanding on your repayment mortgage at any given moment. Pretty useful when you are trying to work out the amount of equity you have in your home and whether you can afford to move.


If you needed further proof of the benefits of saving via an ISA rather than a standard savings account, here it is.

Another stand out free tool is this simple calculator which will quickly work out how much your investment/savings will grow over time. It can take into account charges, inflation, interest rates, tax and regular contributions. Brilliant.


So you’ve built up your pension fund but how much income will it provide you in retirement? This link will show you the best standard annuity rates out there.

But as an alternative to purchasing an annuity this calculator can work out the maximum level of income you can draw from your pension fund via income drawdown.


The inflation figures you read about in the papers are general inflation measures. The actual level of inflation you personally feel depends on how you spend your money. This handy calculator works out your personal rate of inflation.


This petrol calculator allows you to calculate the impact of petrol price rises on your wallet. It also can be used to calculate the cost of a given car journey and the real miles per gallon figure for your car.

Currency Converter

If you are going on holiday then this calculator will tell you how much foreign currency you can expect to get for your pound. Click here to launch