Thermostat Degree-Dollar Calculator
Thermostat Savings Calculator
What this calculator does
Each degree of heating or cooling changes your utility bill. This calculator uses a rough 3% rule of thumb.
The math, with a worked example
Monthly savings = base bill × 0.03 × degrees changed. A $150 base bill with a 3-degree adjustment saves about $13.50 per month.
Why this matters
Heating and cooling dominate most utility bills, and the thermostat is the one control you can move today for free. On a $150 bill, a 3-degree setback is about $13.50 a month — $162 a year — without buying anything.
Methodology and transparency
Savings = base bill × 3% per degree changed. Benchmark: U.S. Department of Energy guidance (archived) pegs setback savings at about 1% per degree per 8 hours — as much as 10% a year from a 7-10°F setback held 8 hours a day. The tool's 3%-per-degree factor matches that rate for a setback held around the clock; a nights-only setback saves roughly a third as much. Real results also depend on climate, insulation, and how much of the bill is actually heating and cooling. Everything runs in your browser; no data is sent or stored.
Last reviewed: 2026-08-08
Common questions
Is 3% per degree accurate?
It is a rough estimate. Real savings depend on climate, insulation, and HVAC efficiency.
Should I change the thermostat by a lot?
Even 1–2 degrees can save money without much discomfort.