Water Heater Cost
Estimate the annual cost of heating water for your household.
About Water Heater Cost
Heating water takes about 8.33 BTUs per gallon per degree Fahrenheit. Scaling that by daily volume and temperature rise, then dividing by efficiency, gives the real draw. Water heating is often the second-largest home energy use, so efficiency and hot water volume heavily shape the bill.
Formula
Water Heater Cost
Energy = gallons x 8.33 lb/gal x temperature rise / efficiency
- temperature rise
- How many degrees the water must be raised
Worked example
With the default values below, Water Heater Cost returns Daily Heating Energy of 18,511. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Hot water per dayminimum 0 gallons
- 40 gallons
- Temperature riseminimum 0 °F
- 50 °F
- Heater efficiencyaccepts 10–100 %
- 90 %
- Electric rateminimum 0 $/kWh
- 0.15 $/kWh
Results
- Daily Heating Energy
- 18,511 BTU
- Daily Electricity
- 5.4 kWh
- Monthly Cost
- $24.77
- Annual Cost
- $297.23
Step by step
- 1Values used
- 2Water Heater Cost
- 3Daily Heating Energy= 18,511 BTU
- 4Daily Electricity= 5.4 kWh
- 5Monthly Cost= 24.77
- 6Annual Cost= 297.23
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Water Heater Cost calculated?
Energy = gallons x 8.33 lb/gal x temperature rise / efficiency Heating water takes about 8.33 BTUs per gallon per degree Fahrenheit. Scaling that by daily volume and temperature rise, then dividing by efficiency, gives the real draw.
Why does Water Heater Cost matter?
Water heating is often the second-largest home energy use, so efficiency and hot water volume heavily shape the bill.
What values do I need to enter?
This calculator takes 4 inputs: Hot water per day, Temperature rise, Heater efficiency, Electric rate. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.