Energy & Utility Calculators

Calculate exactly how much it costs to run any appliance - space heater, air conditioner, EV charger, or anything else. Enter the wattage, usage hours, and your electricity rate to see daily, weekly, monthly, and yearly kWh consumption and dollar cost.

Calculate exactly how many solar panels you need, what the system will cost, how much you will save each year, and when it pays for itself. Enter your monthly electricity usage, local rate, and peak sun hours for a complete solar estimate. The federal solar credit ended after 2025, so it is not in these figures.

Estimate your home's annual heating cost by fuel type. Enter your home's square footage, heating system, insulation quality, and local fuel rate to calculate annual BTU demand, fuel consumption, and total heating cost - broken down by month and compared across all major heating systems.

Estimate your annual air conditioning cost based on home size, AC type, SEER efficiency rating, local cooling degree days, and insulation quality. See monthly breakdowns, peak-season daily costs, and compare savings across SEER ratings - all in seconds.

Calculate your household's daily, monthly, and annual water consumption by entering how many people live in your home and how you use water - showers, baths, toilet flushes, laundry, dishwasher, and outdoor irrigation. See a full breakdown by category and your estimated water bill.

Compare what a bulb costs to run against what it costs to buy, incandescent or halogen against LED. Enter the number of bulbs, bulb types, daily usage hours, and your electricity rate to see annual kWh savings, dollar savings, payback period in days, multi-year projections, and CO2 reduction.

Find out exactly how much you can save by switching to a heat pump. Enter your home size, current heating and cooling systems, climate zone, and energy rates to get annual savings, payback period, and 10-year ROI. The federal credit ended after 2025, so these figures do not count it.

Put a number on an efficiency upgrade before you pay for it. Select the improvements you are considering - insulation, LED lighting, smart thermostat, air sealing, ENERGY STAR appliances, low-flow fixtures, or window treatments - and this calculator estimates annual savings, payback period, and 10-year net savings for each upgrade.

Enter the area and how thick the foam goes, and see the board feet, the kits to buy and the R-value it gives.

Enter your hood's width and how it mounts, and your burners if they are gas, to see the airflow to look for and whether makeup air may apply.

Enter the breaker and what runs on it. You get the amps, with long-running loads counted the way the code counts them.

Enter the wire, the distance and the load. You get the voltage lost on the way there, and the smallest wire that meets your target.

Enter your attic floor to see the net free area you need, how to split it, and what that means in vents.

Enter the bathroom's size and what is in it. You get the CFM HVI recommends, alongside the code's minimum.

Enter the room and the ceiling height to see the blade span and the downrod, and check the fan clears the floor and walls.

Enter what has to stay on and for how long. You get the kilowatt hours needed, and the batteries, checked for both energy and power.

Tell it what runs at the same time and how cold your water comes in. You get the flow, the rise, and the power a unit needs.

Say how big and how damp the room is. You get the pints a day to look for, and what an old unit's label means today.

Enter your attic, what is already up there and your climate zone. You get the bags and the depth to blow, off a real coverage chart.

Choose the room and enter its size to see a range of lumens, how many fixtures that means, and a layout for recessed lights.

Enter your miles, your car and your rate to see what charging at home costs, and how that compares with buying gas.

Choose what has to run together in an outage. You get the running watts and the starting watts a generator has to supply.

Tank size is not the number that matters. Count your busiest hour to find the first hour rating you should shop for.

Enter the room, and how sunny and busy it is. You get the capacity ENERGY STAR's chart calls for, and the next unit size up.