Finance

The Finance section answers eight questions that come up in UK households and small firms all the time. The VAT calculator adds VAT to a net price or strips it out of a gross one, at the standard, reduced or zero rate that HMRC sets for the goods or service.

The loan repayment calculator works in two directions. From an amount, a rate and a term it shows the monthly repayment, the total interest and a full repayment schedule. From a monthly budget it works back to the largest sum that budget could repay. It also shows the APR that fees turn the headline rate into, and compares level repayments with equal capital repayments, where the instalment falls over time.

The savings interest calculator grows a deposit and monthly payments over a term, then works out the income tax the interest causes after the Personal Savings Allowance and the starting rate for savings, with a cash ISA for comparison.

The top slicing relief calculator handles the gain when an investment bond is cashed in or runs past its 5% withdrawal allowance. It works out the chargeable event gain, the income tax on it for onshore and offshore bonds, and the relief that spreads a long-held gain over the years it built up.

The foreign dividend tax calculator follows a dividend from a US, Swiss or other foreign company into a UK account. It shows the withholding the source country takes, the part only that country can refund, the UK dividend tax and the Foreign Tax Credit Relief against it, in a general account or an ISA.

The cost of buying a house calculator adds up what a home costs on top of its price in England, Northern Ireland, Scotland or Wales: Stamp Duty Land Tax, LBTT or LTT for each kind of buyer, the land registration fee, and the quotes entered for conveyancing, a survey and the mortgage.

The tipping guide shows how much to tip abroad and at home, from Italy and the USA to Japan and Egypt: in a restaurant, a bar or a taxi, at the hairdresser, for hotel staff and for a tour guide, in the local currency. It also says whether a service charge or a cover charge is already on the bill.

The pension tax relief calculator shows what a pension contribution costs after tax relief in the current tax year: the basic rate relief the provider adds, the extra relief claimed through Self Assessment, the National Insurance saved by salary sacrifice, and the effect on the personal allowance taper and the High Income Child Benefit Charge.

• What savings will be worth after tax on the interest: the savings interest calculator.
• A price with or without VAT, or the VAT inside a receipt: the VAT calculator.
• The cost of a personal loan, car finance or any fixed rate borrowing: the loan calculator.

Every rate and legal limit is taken from an official source, such as gov.uk, HMRC guidance, legislation.gov.uk or the FCA Handbook, and each page lists those sources with the date they were last checked. Worked examples in the text are produced by the same code that runs the calculator, so the article and the result cannot drift apart. Where a published answer exists, the page runs it through the tool and shows both figures side by side. The tipping guide is the exception: few tourism boards publish a figure for tips, so where none does it uses a national consumer organisation or motoring club and says whose figure each one is.

The full process, including how sources are chosen and how often they are rechecked, is set out in the methodology. When a rate changes, the data is updated first and the pages follow from it.

In most of these tools, figures that are due to change, such as the rates of a new tax year, carry a recheck date in the tool's data file. Once that date passes, an automated test stops the site from building until the figures have been checked again, so an outdated rate cannot stay on a page unnoticed.

These results are estimates for information, not financial advice. A calculator knows only what it is given. A lender's offer can include fees, insurance or a different interest calculation, and a trader's VAT treatment depends on their registration and on how a supply is classified.

Some checks are yours to make against the paperwork. Compare the monthly repayment, the total amount repayable and the APR on a credit agreement with the figures shown here. On an invoice, check that the VAT rate, the net amount and the VAT registration number are all present. Any difference points to something the document includes that the calculation did not.