Everyday calculators

Everyday calculators for the calculations that come up in daily life — tipping, discounts, fuel costs, and more. Quick answers without having to reach for a spreadsheet.

14 calculators

• Alcohol Units Calculator

  Work out UK alcohol units from any drink — pint, glass of wine, spirit, cocktail — using the official NHS formula, and see how it compares to the Chief Medical Officers’ 14-unit weekly low-risk guideline.

• Aspect Ratio Calculator

  Enter a ratio and one dimension to compute the matching width or height in pixels — plus the simplified ratio and the common name (HD 16:9, photo 3:2, cinema, ultrawide).

• BAC Calculator

  Estimate your blood alcohol content from your weight, biological sex, number of standard drinks, and hours since your first drink. Uses the Widmark formula — the same model used in forensic toxicology. Educational only: never use this to decide whether to drive.

• Colour Mixer Calculator

  Enter two hex colours and a blend share to get the mixed colour as hex, RGB, and HSL — using the same linear sRGB formula as the CSS color-mix() function.

• Dice Roller

  Roll any number of dice — d4 to d100 — with an optional modifier. Change any input to reroll.

• Discount Calculator

  Enter the original price and the discount % to see the sale price and what you save. Useful for shop-window quick-checks, voucher codes and stacked promotions.

• Fuel Cost Calculator

  Enter the trip distance, your fuel economy, and the pump price. Get the total cost, fuel used in litres and gallons, and cost per mile or km.

• Gas Mileage Calculator

  Enter how far you drove and how much fuel you used. Get your real-world economy in US mpg, UK mpg, L/100km and km/L — useful for cross-checking the dashboard reading or comparing cars across markets.

• Golf Handicap Calculator

  Convert your Handicap Index into a Course Handicap for any tee using the WHS formula adopted by the USGA and the R&A.

• Mileage Reimbursement Calculator

  Multiply your business-travel distance by an agreed rate per mile or kilometre to total reimbursement owed. Works for IRS standard mileage in the US, HMRC AMAP rates in the UK, CRA per-kilometre allowances in Canada, or any custom employer policy — enter your own rate.

• Snow Day Calculator

  Predict the probability of a school closure tomorrow from forecast snowfall, overnight low, wind speed, and where you live. Treat the result as a guide, not a forecast.

• Tip Calculator

  Enter the bill, the tip % and how many people are splitting it. The calculator returns the tip, the total bill and what each person pays — useful for restaurants, bars, taxis and group meals.

• Tire Size Calculator

  Convert a tire designation (e.g. 205/55R16) into real-world geometry and compare two sizes to see the speedometer error if you switch.

• Typing Speed Calculator

  Convert a number of characters typed in a given time into words per minute. Net WPM penalises uncorrected errors at the standard rate of one word per error.