Calculators

Free indoor air, HVAC and home comfort calculators. Real numbers instead of guesswork.

Pick a tool. Plug in your room details. Get a straight answer in seconds, plus real products that meet the spec.

🌬️ Air Purifiers: Size a purifier by CADR. See what filters really cost each year.

❄️ HVAC: Find the right BTU, tonnage and SEER2 savings for homes and businesses.

🔥 Heating: Match the wattage of a space heater to your room.

💧 Humidity and Water: Size a dehumidifier or humidifier. Pick a water softener. Check water hardness by state.

Every calculator is free and runs right in your browser. Test a room, a home or a budget before you spend a dollar.

👇 Choose a group below and start calculating: Air Purifier, HVAC, Heating, Humidity Control, or Water Filtration.

2 calculators

Size your air purifier right the first time.CalculatorTOOL See what your filters really cost each year.CalculatorTOOL

4 calculators

Find the right BTU for your air conditioner.CalculatorTOOL Find how many tons your home needs.CalculatorTOOL Size a rooftop unit for any business space.CalculatorTOOL See what a SEER2 upgrade saves you.CalculatorTOOL

1 calculator

Find the right wattage for your room.CalculatorTOOL

2 calculators

Pick the right pints per day.CalculatorTOOL Find the right GPD for your home.CalculatorTOOL

2 calculators

Find the right grain capacity.CalculatorTOOL Look up water hardness in your state.CalculatorTOOL