Everyday tools calculators

Quick answers for daily life, with no sign-up and nothing to install.

• 35 calculators
• 18 topics

Clothing & sizes

• Shoe Size ConverterConvert adult shoe sizes between UK, US men’s, US women’s and EU, or find your size from foot length in cm or inches, using the standard sizing formulas.

Clothing & sizing

• Bra Size CalculatorFind your European bra size from underbust and bust measurements in cm or inches, using the EN 13402 band and cup ranges.

Driving & travel

• Speed CalculatorCalculate average speed from distance and time, or the distance covered or time taken, in km/h, mph, m/s or knots, with times shown as h:mm:ss.
• Tyre Size CalculatorWork out a tyre’s overall diameter, sidewall height and revolutions per km from its size (e.g.
• Fuel Cost CalculatorEstimate the fuel and money a trip will take from the distance, your car’s fuel economy and the fuel price, and split it between travellers.
• Gas Mileage CalculatorWork out your car’s real fuel economy from the distance driven and fuel used, shown as MPG (US and UK), km per litre and litres per 100 km.
• Trip Cost Split CalculatorEnter what each traveller paid to get everyone’s fair share and the fewest payments needed to settle up, with optional unequal shares.
• Road Trip Stop Planner CalculatorPlan a long drive: rest breaks every few hours, fuel stops from your tank range, total journey time and arrival time, with a stop-by-stop schedule.

Economics

• GDP CalculatorCalculate gross domestic product from consumption, investment, government spending, exports and imports, with GDP per capita and each component’s share.

Events

• Wedding Guest Budget CalculatorSee what your guest list costs in total and per guest, how much budget is left, and the largest guest list your budget allows with a contingency.

Events & venues

• Event Seating Capacity CalculatorEstimate how many chairs fit in a room in theatre-style rows from its size, seat width, row spacing, aisles and the space kept clear at the front and back.
• Venue Occupancy CalculatorCheck how full a venue is: people present as a percentage of capacity, spaces left, and the headcount at which your alert level is reached.

Family & health

• Height CalculatorEstimate a child’s adult target height and likely range from both parents’ heights with the mid-parental height method of Tanner et al.

Health & routine

• Sleep CalculatorFind bedtimes that fit a set wake-up time, or wake-up times for a given bedtime, by counting roughly 90-minute sleep cycles plus time to fall asleep.

Home

• BTU CalculatorEstimate the cooling capacity a room air conditioner needs in BTU per hour, kW and tons from the room area, sun, occupants and kitchen use.

Home & garden

• Mulch CalculatorWork out how much mulch or bark to buy for a garden bed from its length, width and depth, in cubic metres, litres, cubic yards and bags.

Home & utilities

• Electricity Cost CalculatorWork out how many kilowatt-hours an appliance uses and what it costs to run per day, week, month and year at your own electricity price.

Numbers & codes

• Roman Numeral ConverterConvert any whole number from 1 to 3,999 into Roman numerals, or read a Roman numeral such as MCMXCIV back as a number, with the breakdown shown.

Pets

• Dog Age CalculatorConvert your dog’s age to human-equivalent years using the AVMA chart for small or medium dogs or the 2020 epigenetic formula 16 ln(age) + 31.
• Pet Daily Water Need CalculatorEstimate a dog’s or cat’s daily water need from body weight using the veterinary maintenance formulas, minus the water already in its food.
• Pet Food Portion CalculatorEstimate how many calories your dog or cat needs (RER × life-stage factor) and how many cups, cans or grams of its food that is per day and per meal.

Random & games

• Dice RollerRoll dice online, from a single d6 to 100 dice of up to 1,000 sides, with a modifier, each roll listed, and the minimum, maximum and average.

Shopping & dining

• Tip CalculatorWork out the tip for any bill and percentage, the total to pay, and each person’s share when the bill is split evenly.

Sport & leisure

• Golf Handicap CalculatorEstimate your Handicap Index from your recent 18-hole scores, course ratings and slopes using the World Handicap System rules, plus your course handicap.

Sports

• Cycling Cadence to Speed CalculatorTurn pedalling cadence, chainring, cog and wheel size into road speed in km/h and mph, with gear ratio, metres of development and gear inches.
• Golf Stableford Points CalculatorScore a Stableford round: enter par, stroke index and your gross score for each hole and your playing handicap to get points per hole and in total.
• Baseball Batting Average CalculatorCalculate a baseball batting average from hits and at-bats, plus on-base percentage, slugging percentage and OPS using the official stat definitions.
• Cricket Net Run Rate CalculatorCalculate a team’s cricket net run rate (NRR) across a tournament from runs and overs in each match, using the ICC method with all-out innings at full quota.
• Cricket Required Run Rate CalculatorFind the required run rate in a cricket chase from the target, current score and overs bowled, with runs needed, balls left and current run rate.
• Basketball Effective Field Goal Percentage CalculatorCalculate basketball effective field goal percentage (eFG%), plain FG% and true shooting percentage (TS%) from makes and attempts.
• Tennis Match Win Percentage CalculatorWork out a tennis win–loss percentage for matches, sets and games, and how many wins in a row you need to reach a target win rate.
• Darts Checkout CalculatorEnter the score you have left to see whether it can be finished in one visit, the fewest darts needed and one double-out checkout route.

Weather

• Wind Chill CalculatorCalculate the wind chill index from air temperature and wind speed in °C or °F, using the formula adopted by the US and Canadian weather services in 2001.
• Heat Index CalculatorCalculate the heat index (apparent temperature) from air temperature and relative humidity in °C or °F, using the US National Weather Service algorithm.
• Dew Point CalculatorFind the dew point from temperature and relative humidity, or the relative humidity from temperature and dew point, in °C or °F with the Magnus formula.

Other subjects