Science & Weather Calculators
Physics, chemistry, and weather in one place. Calculate wind chill, heat index, and dew point with official formulas, work out half-life and Ohm’s law, and check the moon phase and sunrise or sunset.
12 free calculators · no sign-up · instant results
Weather
Physics & Space
Carbon Footprint Calculator
Estimate your annual CO₂ emissions in tons
Sunrise & Sunset Calculator
Sunrise, sunset, and day length for any location
Moon Phase Calculator
Moon phase, illumination, and next full moon
BTU Calculator
Cooling BTUs a room needs — AC sizing
Half-Life Calculator
Remaining amount, decay constant & mean lifetime
Density Calculator
Density from mass and volume in any units
Ohm’s Law Calculator
Solve volts, amps, ohms & watts from any two
Horsepower Calculator
HP from torque and RPM, with kW and PS
Molarity Calculator
Molar concentration from mass, molar mass & volume
Frequently asked questions
Which formulas do the weather calculators use?
The Wind Chill and Heat Index calculators use the official U.S. National Weather Service formulas, so results match what forecasters report.
What can I use Ohm’s law calculator for?
It solves for voltage, current, resistance, or power when you know any two — handy for electronics, wiring, and physics homework.