15 tools Finance
Mortgage, loan, interest and percentage maths with full schedules.
Your files stay on your device. The tool works directly in your browser, using your device to process your files. Nothing is sent to our servers, and we never receive, store, or see your files or figures.
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Mortgage calculator
Work out the full monthly cost of a home loan, covering principal, interest, tax, insurance and PMI, with a year-by-year amortisation schedule.
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Loan calculator
Find the monthly payment, total interest and full repayment schedule for any fixed-rate loan, whether car, personal, student or business.
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Compound interest calculator
See how savings and investments grow over time, with regular contributions and any compounding frequency, plus a year-by-year balance table.
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Percentage calculator
Work out a percentage of a number, express one number as a percentage of another, or find the percentage increase or decrease between two values.
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Amortization calculator
Generate a full amortisation schedule payment by payment, find the crossover month, and see what an extra payment each month actually saves.
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Refinance calculator
See what refinancing really saves: the new payment, how many months it takes to earn back closing costs, and what restarting the term costs you.
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Retirement calculator
Project a retirement pot in today's money, see how much of it is growth rather than contributions, and estimate a sustainable income from it.
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Salary calculator
Convert pay between hourly, daily, weekly, monthly and annual, accounting for hours worked and unpaid leave.
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Tip calculator
Work out the tip and the total, split it between any number of people, and round the tip or the total up to a clean number.
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Discount calculator
Work out a sale price, stack two discounts correctly, or find what percentage off you actually got.
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Sales tax calculator
Add sales tax to a price or strip it back out of a total, with the arithmetic that catches almost everyone shown explicitly.
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VAT calculator
Add VAT to a net price or extract it from a gross total, with rates for the UK, EU and other common jurisdictions.
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ROI calculator
Calculate return on investment as a percentage and as an annualised rate, so holdings of different lengths can actually be compared.
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Average Down Calculator
Add every purchase of a stock and see your true average price, the break even price once fees are counted, and how much more you would have to buy to reach the average you want.
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Position Size Calculator
Size a trade from the loss you can afford rather than the cash you happen to have. Enter your capital, your risk per trade and your stop, and get the quantity, the money at risk and the reward to risk ratio.
Money maths you can check
Financial calculators are the ones people most often need to trust and least often get to verify. Every tool here shows its working: the formula it uses, the assumptions it makes, and a schedule you can read line by line rather than a single number you have to take on faith.
They also run entirely on your device. Your salary, your debts and your deposit are never transmitted, which matters more here than in any other category on this site.
Which calculator do you need?
- Buying a home: the mortgage calculator includes property tax, insurance and PMI, so the monthly figure is the one that will actually leave your account.
- Replacing a mortgage you already have: the refinance calculator works out the break-even on closing costs and what restarting the term quietly costs you.
- Borrowing anything else: the loan calculator covers car, personal and student loans, and shows how much term length costs you.
- Saving or investing: the compound interest calculator handles regular contributions and any compounding frequency.
- Buying more of a stock that has fallen: the average down calculator gives your real average price, your break even after fees, and the exact quantity a target average would cost.
- Deciding how much to buy: the position size calculator sizes a trade from the loss you can afford rather than the cash in the account.
- Everyday percentages: the percentage calculator covers discounts, tax, tips and percentage change.
A note on accuracy
These calculators use standard published formulas and are accurate to the inputs you give them. What they cannot know is your credit profile, the fees a particular lender charges, or how rates will move. Treat every result as a well-informed estimate for comparing options, and get the real numbers from a lender's Loan Estimate before committing to anything.
