Finance & Money Calculators
Thirty-eight calculators covering the three money questions that matter — what borrowing costs, what saving builds, and what you actually keep after tax.
Three groups, three different questions
Money tools split cleanly. Borrowing tools answer "what will this cost me?" — repayments, total interest and the true annual rate. Saving and investing tools answer "what will this become?" — compounding, targets and returns. Pay, tax and business tools answer "what do I actually keep?" — take-home pay, VAT and margin. Working out which question you are asking is usually the fastest route to the right calculator.
The number to compare is never the monthly payment
A longer term always produces a smaller monthly payment and a larger total cost, so comparing offers on the monthly figure alone reliably picks the more expensive loan. Compare total interest instead, and use the APR Calculator when fees are involved — APR is the only figure that folds interest and mandatory charges into something comparable across products. The Loan Calculator and Mortgage Calculator both show total interest alongside the monthly payment for exactly this reason.
Buying a property is taxed differently in each UK nation
There is no single UK stamp duty. England and Northern Ireland charge SDLT, Scotland charges LBTT and Wales charges LTT, each with its own thresholds, its own first-time buyer treatment and a completely different mechanism for second homes — so a figure read off an English calculator can be thousands out elsewhere. Use the Stamp Duty Calculator, the LBTT Calculator or the LTT Calculator for your own purchase, and see all three set side by side at twenty price points on our UK property tax comparison. Once the purchase is done, the Mortgage Overpayment is where the larger sums are.
Compounding rewards time more than amount
The single most useful thing the Compound Interest demonstrates is that starting earlier beats saving more. Money invested for thirty years at a modest rate typically beats a much larger sum invested for ten, because each year's growth becomes next year's principal. Run the same figures through the Simple Interest to see the gap open up, and use the Inflation Calculator to convert any long projection back into today's purchasing power before you get too excited.
Business pricing is where small errors compound fastest
Markup and margin are different percentages of different bases, and confusing them is the most common pricing mistake in small business. A 50% markup on cost is a 33% margin on price. Use the Markup Calculator to go from cost to price and the Profit Margin to check what margin that price actually delivers, then confirm the volume you need with the Break-Even.
What these tools assume
Every finance calculator here uses a simplified model: fixed rates, regular payments, no missed months and no product-specific fees unless you enter them. They are for planning and comparison, not for advice — figures from a lender's illustration or an accountant will always beat an estimate. Tax tools follow current published UK rates and bands; check the year shown on the page before relying on the result.
Related categories
Every tool listed here produces an estimate from the numbers you enter and the assumptions stated on its own page. None of them accounts for fees, charges, tax treatment or your individual circumstances, and rates and thresholds change. Tool Corner is not authorised by the Financial Conduct Authority and does not give financial advice. Speak to a qualified adviser before making a financial decision.
Each tool states its own assumptions and sources. Read the full disclaimer.