About Home Gear Calculators

HomeGearCalc is a free, independent set of calculators for home equipment and aquariums. The home tools cover propane tank burn time, pool salt, generator watts, room air conditioner BTU, and tankless water heater flow. The aquarium section covers tank volume, standard tank dimensions, heater watts, and a stocking rule of thumb.

What a result is

Each tool page states the formula it uses. Propane uses 91,502 BTU per gallon. Pool salt uses 8.3454 pounds of water per gallon in the ppm conversion. Generator size adds running watts, the largest extra starting watt, and 20 percent. Room air conditioning follows the ENERGY STAR room-size bands and the shade, sun, people, and kitchen adjustments. Tankless water heat uses GPM x rise / 6.83 for electric kilowatts. Aquarium gallons are cubic inches divided by 231. Heater watts use 0.5 watt per gallon per degree F, shown next to Aqueon's published chart where that chart has a row. Stocking is the inch-per-gallon rule, labeled as a rule of thumb.

What a result is not

These are planning estimates. They are not an electrical design, a gas piping design, a pool chemistry prescription, or a veterinary opinion about a fish. Rating plates, local code, and the equipment manual win when they disagree with a preset on this site.

Your numbers

The calculators run in your browser. The gallons, watts, and temperatures you type are not uploaded to HomeGearCalc. There is no account. See the privacy policy for hosting logs and for advertising cookies if ads are added later.

Questions and corrections go to [email protected] or the contact page.