Free, real calculators for everyday home decisions, no email signup, no ads blocking the results. Pick one below.
Air Conditioner BTU Calculator
Find the right AC size for any room based on ENERGY STAR guidance, accounting for ceiling height, sun exposure, and occupancy.
Internet Speed Calculator
Figure out exactly how many Mbps your household needs based on streaming, gaming, work from home, and smart devices.
Appliance Running Cost Calculator
See exactly what any appliance costs to run per day, month, and year based on its wattage and your real electricity rate.
Thermostat Savings Calculator
Estimate your real annual savings from switching to a smart thermostat, based on ENERGY STAR data.
LED Bulb Savings Calculator
See exactly how much switching to LED bulbs saves you per year based on real wattage and your electricity rate.
Water Heater Size Calculator
Find the right water heater tank size for your household based on DOE peak-hour demand guidance.
Want the full rundown on why each of these matters? Read 6 Free Calculators That Take the Guesswork Out of Home Decisions.