Don’t know your energy rate off the top of your head? No problem, all you need is last December’s bill to find out.
How to calculate your annual heating costs
| STEPS | EXAMPLE | NOTES |
|---|---|---|
| 1. Find monthly gas bills for 12 recent months | Can be any 12 consecutive months, e.g., May 2023-April 2024. | |
| 2. Add up the total charges | Total for 12 months: $1,200 | Add the total from each bill for the 12 month period. |
| 3. Find the average charges for the summer months | Total for June-August = $90. $90/3= $30 | This will be your average monthly charges for water heating and cooking. Look at gas bills for June through August, add the total charges and divide by 3. |
| 4. Find annual charges for non-home heating | Average for non-home heating = $30. $30x 12 = $360 | Take the average from the previous step (step 3) and multiply by 12. |
| 5. Find your annual heating costs | $1200 – $360 = $940 | Take the total from step 2; subtract the total from step 4. This is your annual cost for home heating. |
| 6. How much will my utility bill change with a heat pump? | If the calculator shows “increase of 10%,” your annual heating costs will increase by: 0.10 x $940 = $94 | Take the percentage increase or decrease indicated by the calculator; multiply by the total from step 5. |
| 7. How will this affect my monthly utility bills? | Your winter monthly utility bills will increase by about: $94/3 = $31.30 per month | Take the total from step 7 and divide by 3 (for the three winter months) to find the average increase or decrease for these three months. (To see changes to cooling bill, see steps below) |
How to calculate your annual cooling costs
| STEPS | EXAMPLE | NOTES |
|---|---|---|
| 1. Find monthly electricity bills for 12 recent months | Can be any 12 consecutive months, e.g., May 2023-April 2024 | |
| 2. Add up the total charges | Total for 12 months: $1,400 | Add the total from each bill for the 12 month period. |
| 3. Find the average charges for the winter months | Total for December-February = $240. $240/3=$80 | This will be your average monthly electricity charges for everything except cooling. Look at electricity bills for December through February, add the total charges and divide by 3. |
| 4. Find annual electricity charges for non-home cooling | Average for non-home cooling = $80. $80 * 12 = $960 | Take the average from the previous step (step 3) and multiply by 12. |
| 5. Find your annual cooling costs | $1400 – $960 = $440/year | Take the total from step 2; subtract the total from step 4. This is your annual cost for home cooling. |
| 6. How much will my annual utility bill change with a heat pump? | If the calculator shows “decrease of 15%,” your annual cooling costs will decrease by: .15 x $440 = $66 | Take the percentage decrease indicated by the calculator; multiply by the total from step 5. |