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.
25 calculators
- 3x Rent Rule Calculator
Most US landlords require gross monthly income of at least three times the rent. This calculator works it both ways: max rent for your income, and required income for a target rent.
- Acceptance Rate Calculator
Work out what percentage of applicants get in. Enter the number who applied and the number accepted to see the acceptance rate, rejection rate, and Carnegie selectivity band — plus the optional yield rate if you know how many enrolled.
- Alcohol By Volume (ABV) Calculator
Work out the alcohol by volume of your beer, wine, cider or mead from a pair of specific-gravity readings — using both the popular simple formula and the more accurate advanced (Hall) formula used for high-gravity brews.
- 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.
- BBQ Party Calculator
Tell us who is coming and how long the party runs. We work out the meat to buy raw, the cooked portion per guest, sides, buns, drinks and ice.
- Car vs Bike Cost Calculator
Compare how much a car and a bike really cost over the same distance. Enter annual mileage and the all-in cost per unit for each mode — the calculator shows annual and multi-year savings side by side.
- CO₂ From Breathing Emission Calculator
Enter body weight, activity level, and duration — the calculator returns exhaled CO₂ mass and volume from human respiration using published metabolic-equivalent (MET) values.
- 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.
- Perfect Pancake Batter Calculator
Pick a style, enter how many pancakes you want, and get the batter ingredients in grams, millilitres, cups and spoons. Recipes come from King Arthur, Serious Eats and Delia Smith — no guesswork.
- Pizza Calculator
Tell us how many adults and kids are coming and the pizza size, and we will work out how many pizzas to order using the standard slice-per-guest rule.
- 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.
- Streaming Services Cost Calculator
Add up everything you stream and find out what those subscriptions really cost you over 5, 10, or 20 years — including annual price hikes and the investment returns you give up.
- Subscription Cost Calculator
Turn any recurring subscription into a daily, weekly, monthly, annual and lifetime cost — and see what optional price increases compound to over time.
- 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.
- Trick-or-Treat Candy Calculator
Tell us how many trick-or-treaters you expect and how many pieces each one gets. We work out the total candy, the number of fun-size bags to buy and the likely cost.
- 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.