All Air Purifier, HVAC, and Home Comfort Calculators in One Place
Free tools to help you size and shop for air purifiers, HVAC equipment, and home comfort products based on real math, not guesswork. Enter your room details and get a straight answer, plus real currently-available products that meet the spec.
Air Purifier Calculators
Use the calculator below to size your air purifier correctly the first time.
CADR Calculator
See what you’ll really pay to keep your air purifier’s filters replaced.
Filter Replacement Cost Calculator
HVAC Calculators
Use the calculator below to find the right BTU rating for your air conditioner.
BTU Calculator
Find out how many tons of central air conditioning your home needs.
AC Tonnage Calculator
Size a commercial rooftop unit for an office, retail space, restaurant, warehouse, or data center.
Commercial HVAC Tonnage Calculator
Estimate your real annual dollar savings from upgrading to a higher SEER2-rated system.
SEER2 Energy Savings Calculator
Heating Calculators
Find the right wattage space heater for your room size.
Space Heater Wattage Calculator
Humidity Control Calculators
Find the right pint-per-day capacity dehumidifier for your space.
Dehumidifier Pint Calculator
Find the right GPD output humidifier for your home’s size and construction.
Humidifier GPD Calculator
Water Filtration Calculators
Find the right grain capacity water softener for your household.
Water Softener Grain Calculator
Look up typical water hardness by state, sourced from real USGS groundwater data.
Water Hardness by State Calculator
