Everyday Calculators

ArrayKit's everyday calculators answer the small questions of home and school life. Teachers, families and friends settle choices with Spin the Wheel, which picks a winner from your list, Coin Flip, which tosses one coin or a hundred, the Random Name Picker, which draws winners or shuffles a list, and the Dice Roller, which rolls dice from d4 to d100. Students can work out a grade point average with the GPA Calculator and the score they need on a final with the Grade Calculator. The Sleep Calculator suggests bedtimes and wake times from 90-minute sleep cycles, and the Unit Conversion Calculator converts length, weight, temperature, volume and more. For groups, the Secret Santa Generator draws names with exclusions and the Random Team Generator splits a list into balanced teams. Sizing tools convert shoe, ring, clothing, hat and mattress sizes between countries, estimate a bra size and work out TV dimensions and viewing distance. In the kitchen, the Cooking Measurement Converter turns cups into grams and the Recipe Scaler halves or doubles a recipe, while the Unit Price Calculator and Pizza Size Calculator find the better deal. You can also turn dog and cat years into human years, look up your Chinese zodiac sign, estimate a golf handicap or convert mouse sensitivity between games. Everything is calculated in your browser, so what you enter stays on your device.

  • GPA Calculator — Calculate your grade point average from course grades and credit hours.
  • Grade Calculator — Compute a weighted course grade and the score needed on the final exam.
  • Sleep Calculator — Find the best bedtimes or wake times based on 90-minute sleep cycles.
  • Golf Handicap Calculator — Estimate a golf handicap index from your recent scores and course data.
  • Dice Roller — Roll any number of dice, from d4 to d100 or custom dice, with modifiers and totals.
  • Shoe Size Converter — Convert shoe sizes between US, UK, EU and centimeters for men and women.
  • Bra Size Calculator — Estimate your bra size from band and bust measurements in US, UK and EU.
  • Unit Conversion Calculator — Convert length, weight, temperature, volume, area, speed and more.
  • Height Calculator — Convert height between feet/inches and cm, and predict a child’s adult height.
  • Cooking Measurement Converter — Convert cups, spoons, millilitres, grams and ounces using ingredient density.
  • Pet Age Calculator — Convert dog and cat years to human years using size-adjusted ageing curves.
  • Ring Size Converter — Convert ring sizes between US, UK, EU, Japan, diameter and circumference.
  • Clothing Size Converter — Convert women’s and men’s clothing sizes between US, UK, EU, Italian and French charts.
  • Unit Price Calculator — Compare pack sizes by price per 100 g, 100 ml or piece and spot the real bargain.
  • Chinese Zodiac Calculator — Your animal sign and element from your birth date, honouring Chinese New Year cutoffs.
  • Recipe Scaler — Scale any recipe by servings, a multiplier or a change of pan size.
  • Random Name Picker — Draw winners, shuffle a list or split teams, with a seed you can share.
  • Coffee Ratio Calculator — Solve coffee, water or ratio for any brew method, in grams and cups.
  • Hat Size Converter — Convert head circumference to US, UK, EU and S/M/L hat sizes.
  • Pizza Size Calculator — Compare pizzas by area and price per square inch, and size an order for a group.
  • TV Size Calculator — Screen width, height, area and the right viewing distance for any diagonal.
  • Mattress Size Converter — Match US, UK, European and Australian bed sizes, and check they fit the room.
  • Secret Santa Generator — Draw Secret Santa names with couple and past-match exclusions, then hand out matches by passing the device or private links.
  • Spin the Wheel — Add names or options, spin a colorful wheel and let chance pick the winner, with weights, sound and history.
  • Coin Flip — Flip a fair coin online with a 3D animation, multiple coins at once, streaks and running totals.
  • Random Team Generator — Split a list of names into balanced random teams by team count or team size, with optional skill ratings.
  • Mouse Sensitivity Converter — Convert mouse sensitivity between games and get cm/360 and eDPI so your aim feels the same everywhere.

Guides

  • Spin the Wheel Pickers, Explained — How a spin the wheel picker chooses a winner, whether a random name picker wheel is fair, how weights and duplicates change the odds, and tips for giveaways.
  • Grade Point Average (GPA), Explained — How to calculate GPA from letter grades and credit hours, the 4.0 GPA scale with plus and minus values, weighted vs unweighted GPA, and cumulative GPA.

Frequently asked questions

What can I do with these everyday calculators?
Pick a winner, flip coins, roll dice, draw Secret Santa names and split a group into teams. Work out a GPA, a course grade or a bedtime that fits your sleep cycles, and convert units, heights, cooking measures and shoe, ring, clothing, hat and mattress sizes. Others estimate a bra size, scale recipes, set a coffee-to-water ratio, compare unit prices and pizza deals, size a TV for your room, turn pet years into human years, find your Chinese zodiac sign, estimate a golf handicap and match mouse sensitivity between games.
How do I pick a random winner or split a group fairly?
Spin the Wheel suits a classroom, with optional weights and a history of results, while the Random Name Picker draws one or several winners or shuffles a list, and the Random Team Generator splits names into teams, balanced by skill if you add ratings. Spin the Wheel, Coin Flip and the Dice Roller use your browser's cryptographic random number generator, and the wheel and the coin settle the result before the animation starts. The Random Name Picker and Random Team Generator can work from a seed, so a draw can be rerun and checked, and the Secret Santa Generator keeps couples and last year's pairs apart.
Do these calculators send what I type anywhere?
No. Every calculation runs in your browser, so grades, measurements, names and lists stay on your device and are not uploaded to ArrayKit. A few tools, such as Coin Flip, the Random Team Generator and the Mouse Sensitivity Converter, remember your last settings or list in this browser only. A shared Spin the Wheel link carries the list in the address, and a Secret Santa private link carries one person's match inside the link, so whoever has the link can see what it holds.
How accurate are the results?
They follow standard formulas and charts, so treat them as close estimates. The GPA Calculator uses a 4.0 scale with plus and minus grades, which may differ from your school's, and the Sleep Calculator assumes 90-minute cycles, an average that varies from person to person. Size converters follow standard charts, but brands cut differently and the bra size is an estimate rather than a fitting. The golf result estimates a Handicap Index rather than replacing an official one, and the Cooking Measurement Converter asks for the ingredient before turning cups into grams, because a cup of flour weighs less than a cup of sugar.
Can I use these calculators on a phone or in a classroom?
Yes. They run in current mobile and desktop browsers with nothing to install. Spin the Wheel has a full screen mode for a classroom, the Secret Santa Generator can hand out matches by passing one phone around so each person sees only their own, and Coin Flip answers a tap or the space bar.