Money, mortgage & debt calculators
The view a professional takes of your money: what it costs, what it earns, and how long it lasts. Free UK calculators for clearing debt sooner, overpaying a mortgage, renting against buying, a house against shares, and what inflation does to cash. No sign-up to use them, and every figure is arithmetic from your own inputs, not advice.
Mortgages: your equity, repayments and rate
Credit card payoff calculator
Enter your card balance, its APR and what you pay each month to see how long the card takes to clear and the total interest. Then add an amount on top: the payoff line shortens as you do, and the headline says how much sooner you are debt-free and what you save. Figures assume no new spending.
Debt snowball and avalanche calculator
The snowball method pays your smallest balance first for quick, motivating wins; the avalanche method pays your highest rate first to save the most interest. Add each of your debts with its balance and rate, set what you can pay in total each month, and compare the two on your debt-free date and total interest.
Minimum payment calculator
Paying only the minimum stretches a card over many years, because the minimum shrinks as the balance falls. Enter your balance, APR and minimum terms to see how long it takes and the interest you pay, then add an amount on top to watch the payoff line shorten. Figures assume no new spending on the card.
Balance transfer calculator
A 0% balance transfer moves card debt to a new card that charges no interest for a set period, for a one-off transfer fee. Enter your balance, the fee, the 0% months and your monthly payment to see the fee, how long the debt takes to clear, any interest once the 0% ends, and the total cost.
Debt consolidation calculator
Consolidating combines several debts into one fixed monthly payment at a single rate. Enter your total balance, a loan rate and a term to see the new monthly payment and total interest, and how much interest you save and how much sooner you clear it compared with leaving the balance on a card at the minimum.
Personal loan calculator
A personal loan is repaid in equal monthly instalments over a fixed term. Enter how much you want to borrow, the APR and the term to see your monthly repayment, the total interest, and the total you repay. The rate you are actually offered depends on your credit profile and the lender.
Mortgage overpayment calculator
Overpaying a repayment mortgage cuts both its length and its interest, because every extra pound comes straight off the balance that interest is charged on. Enter what you owe, your rate and the years left, then add a monthly overpayment or a lump sum to see how much sooner it ends and what you save.
Rent vs buy calculator
Buying builds equity but costs stamp duty, fees, interest and upkeep; renting leaves that money free to invest. This compares the two fairly: both households spend the same each month, and whichever pays less invests the difference. The lines show each one's net worth over time, at growth rates you choose.
House vs shares: which builds more wealth?
A home is bought mostly with borrowed money, so its gains and falls are magnified, and it costs interest, stamp duty, upkeep and selling fees while saving you rent. Shares carry no mortgage but can be taxed outside an ISA. Put the same money into each, set the growth rates, and see which comes out ahead.
Cash vs investing calculator
Cash that earns nothing loses buying power every year prices rise: at 3% inflation, £10,000 kept for 10 years buys what about £7,441 buys today. Add a savings rate and a stated investment return to see three paths in today's pounds, and the gap between them: the opportunity cost of holding cash.
Voluntary National Insurance calculator
A whole year of voluntary Class 3 National Insurance costs £956.80 at today's rate and adds about £358.50 a year to the new State Pension, so it repays itself in about 2.7 years of drawing it. You can only fill the last six tax years: the oldest, 2020-21, closes on 5 April 2027. In some cases it adds nothing, so check your forecast first.
Track every debt in one place
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