Free tools for finding your temperature

Three quick calculators built on published formulas and studies. Each one gives you a link to share, so you can settle the thermostat debate with numbers.

• 65°where the calculator starts

  Ideal sleep temperature calculator

  Answer six quick questions and get your ideal sleep temperature for the bedroom, with the research behind each adjustment and a result you can share.

  Open the tool →
• +15°what full sun can add to the heat index

  Feels like temperature calculator

  Enter temperature, humidity and wind to get the heat index or wind chill (NWS formulas), the dew point, and what to set your car and thermostat to.

  Open the tool →
• 117°a parked car on a 72°F sunny day

  Hot car calculator

  Pick the outside temperature and the minutes parked to see how hot a closed car gets in the sun, based on measured data. Share it with someone who needs to see it.

  Open the tool →

Want the reasons behind the numbers? Read the Just Right guides.