Cost to Heat a Home in Idaho: Gas vs Propane vs Heat Pump
In Idaho the cheapest heat last winter was natural gas at $7.37 per MMBtu delivered; electric resistance cost $36.28 — EIA prices, October 2025 to March 2026.
· Source: EIA STEO September 2026, Natural Gas Monthly, SHOPP · EPM Table 5.6.A (July 2026 data) · next: EIA Winter Fuels Outlook Oct 6, weekly SHOPP prices from October
On this page: CalculatorTableHow we calculatedSources
Jump to calculator ↓Prefilled with Idaho's last-winter EIA averages; the second preset applies EIA's national outlook. Per-unit rates only; leave out the fixed monthly charge.
Advanced — efficiencies, gas unit, COP, seasonal load
Sliders scale the prefilled prices to test sensitivity; the numeric fields stay the precise inputs. Presets:
- Cheapest last winter
- Natural gas · $7.37/MMBtu
- Most expensive
- Electric resistance · $36.28/MMBtu
- Natural gas
- $0.70/therm, winter avg
- Propane
- $2.36/gal (state)
- Heating oil
- $3.94/gal (national)
- Electricity
- 12.38¢/kWh, winter avg
- Heat pump COP basis
- NEEP median, 3.20/2.17/1.90
- Heating degree-days, NOAA state
- 4,724 (Oct 2025–Mar 2026)
- EIA STEO Mountain division HDD
- 3,138 last · 3,929 forecast
- Federal credit
- §25C ended 31 Dec 2025
Why this number
Idaho paid 12.38¢/kWh for electricity last winter — 3 of 35 on this list of 35 cold-weather states — and $0.70 per therm for gas (1 of 35); propane ran $2.36/gal (15 of 35) and heating oil $3.94/gal (19 of 35). Put on one basis, dollars per million Btu delivered, natural gas was the cheapest heat at $7.37 and electric resistance the dearest at $36.28 — a 29-dollar gap per MMBtu, or about $1,735 over a 60-MMBtu season.
Price basis: Idaho’s fuel prices are last winter’s measured EIA and SHOPP averages; the this-winter column scales each by EIA’s national STEO change for that fuel — a labelled estimate, not a state forecast.
Idaho heating cost per MMBtu, fuel by fuel
| Heating option | $/MMBtu delivered, last winter | Season cost at 60 MMBtu | This winter, EIA outlook applied |
|---|---|---|---|
| Natural gas furnace (95% AFUE) | $7.37 | $442 | $6.65 (-10%) |
| Propane furnace (92% AFUE) | $28.09 | $1,685 | $26.77 (-5%) |
| Heating oil boiler (85% AFUE) | $33.47 | $2,008 | $45.02 (+35%) |
| Heat pump at 47°F (COP 3.20) | $11.34 | $680 | $11.63 (+3%) |
| Heat pump at 17°F (COP 2.17, NEEP median 3-ton ducted) | $16.72 | $1,003 | $17.15 (+3%) |
| Heat pump at 5°F (COP 1.90) | $19.10 | $1,146 | $19.59 (+3%) |
| Electric resistance (COP 1.00) | $36.28 | $2,177 | $37.22 (+3%) |
The season column is an illustrative 60 MMBtu of delivered heat; in Idaho that puts natural gas at $442 and electric resistance at $2,177 for the winter. The this-winter column applies EIA’s national STEO change per fuel to Idaho’s own price (electricity +3%) — direction, not a state forecast.
The prices behind the table
| Price | Last winter average (Oct 2025–Mar 2026) | Latest published reading | Source and basis |
|---|---|---|---|
| Electricity | 12.38¢/kWh | 13.73¢/kWh (July 2026) | EIA Electric Power Monthly 5.6.A; winter average from the monthly editions |
| Natural gas | $0.70/therm ($7.30/Mcf, 6 of 6 months reported) | $11.33/Mcf (June 2026, shoulder-season price) | EIA Natural Gas Monthly, residential price by state; 1 Mcf = 10.38 therms |
| Heating oil | $3.94/gal | $5.30/gal (STEO forecast, national) | EIA STEO national average Oct 2025–Mar 2026 — no SHOPP state or regional heating oil series |
| Propane | $2.36/gal | $2.40/gal (week of 2026-03-30) | EIA SHOPP weekly survey, Idaho, Oct 2025–Mar 2026 average |
Idaho’s June gas figure ($11.33/Mcf) runs 1.6× its winter average ($7.30) because EIA’s residential price is average revenue per Mcf with the fixed charge folded in; the high-volume winter months are the closest published proxy for the marginal rate this page needs.
What Idaho’s utilities charge
| Utility (largest by customers) | Residential customers | ¢/kWh (EIA-861 2024) | Resistance $/MMBtu | Heat pump at 17°F $/MMBtu |
|---|---|---|---|---|
| Idaho Power Co | 525,751 | 11.8¢ | $34.58 | $15.94 |
| Avista Corp | 128,226 | 11.6¢ | $34.00 | $15.67 |
| PacifiCorp | 74,170 | 12.1¢ | $35.46 | $16.34 |
The statewide 12.38¢ hides a 0.5¢ spread between Idaho’s largest utilities. The ZIP lookup finds yours.
How Idaho homes are heated
| Main heating fuel | Idaho homes | US homes |
|---|---|---|
| Natural gas (utility) | 51.4% | 46.8% |
| Electricity | 35.0% | 40.8% |
| Propane (bottled, tank or LP gas) | 5.3% | 4.9% |
| Heating oil or kerosene | 1.4% | 4.1% |
| Wood | 5.6% | 1.4% |
Natural gas heats 51.4% of Idaho’s 693,821 occupied homes against 46.8% nationally, with electricity at 35.0%, propane at 5.3% and heating oil at 1.4%. That lines up with the table above: natural gas was also Idaho’s cheapest heat last winter at $7.37 per MMBtu.
What the numbers say about Idaho
At last winter’s average prices, the cheapest way to heat a home in Idaho was natural gas at about $7 per million Btu delivered, and the most expensive was electric resistance at $36 — a 4.9× spread between the two columns. Gas beat a cold-climate heat pump at 17°F (COP 2.17) by $9.35/MMBtu, and at 47°F (COP 3.2, $11.34) the heat pump still trails. At Idaho’s winter rates the economic balance point lands above 47°F (COP 4.92 needed against 3.20 available), so the furnace is cheaper at every rated temperature. No EIA state or regional heating-oil series exists for Idaho; the oil row is the national STEO average ($3.94/gal last winter, $5.30 forecast) and is labelled as such. Propane averaged $2.36/gal in the state survey, with a national -5% outlook for this winter.
Heating degree-days: Idaho’s own figure and the EIA division forecast
Idaho itself logged 4,724 population-weighted heating degree-days from October 2025 to March 2026 (NOAA Climate Prediction Center state series, base 65°F), against 3,500 for the contiguous US. The month-by-month table below is a different, coarser series — EIA STEO Mountain census division degree-days, the only one with a forecast for the coming winter; it groups Idaho with its neighbours and is not a Idaho figure:
| Last winter (actual) | HDD | This winter (STEO forecast) | HDD |
|---|---|---|---|
| Oct 2025 | 311 | Oct 2026 | 335 |
| Nov 2025 | 483 | Nov 2026 | 606 |
| Dec 2025 | 643 | Dec 2026 | 866 |
| Jan 2026 | 800 | Jan 2027 | 853 |
| Feb 2026 | 547 | Feb 2027 | 696 |
| Mar 2026 | 355 | Mar 2027 | 574 |
| Oct–Mar total | 3,138 | Oct–Mar total | 3,929 |
January in the EIA Mountain census division (the coarse series that groups Idaho with its neighbours) averaged about 39°F last winter (65°F minus degree-days per day) and is forecast at 37°F for January 2027, a season move of +791 degree-days. Degree-days set how much heat Idaho needs, the table above sets the price per unit, and the bill jump calculator multiplies the two.
Where the heat pump crosses over in Idaho
At last winter’s averages of 12.38¢/kWh and $0.70/therm, a heat pump beats a 95% gas furnace whenever its COP exceeds 4.92. Idaho’s economic balance point on the NEEP median curve is above 47°F (COP 4.92 needed against 3.20 available), so the furnace is cheaper at every rated temperature; the crossover tool runs seven named units at Idaho’s prices and the dual-fuel calculator turns the answer into a changeover setting.
From October 6 the EIA Winter Fuels Outlook adds household expenditure by region and the weekly SHOPP survey restarts, giving Idaho fresh state propane readings on the weekly tracker .
Frequently asked questions
What is the cheapest way to heat a home in Idaho?
On last winter’s EIA average prices, natural gas at about $7.37 per million Btu delivered, against a cold-climate heat pump at $16.72 and propane at $28.09. Idaho’s ranking uses a 95% gas furnace, 92% propane furnace, 85% oil boiler and a heat pump at COP 2.17; it is per unit of heat, so Idaho’s fixed monthly charges and equipment prices sit outside it.
Is a heat pump cheaper than gas in Idaho?
At Idaho’s last-winter averages of 12.38¢/kWh and $0.70/therm, a heat pump needs a COP above 4.92 to beat a 95% furnace. Against Idaho’s required COP 4.92, the NEEP medians (3.20/2.17/1.90 at 47/17/5°F) mean the heat pump loses at every rating point in Idaho; the balance point is above 47°F (COP 4.92 needed against 3.20 available), so the furnace is cheaper at every rated temperature.
How much will heating oil and propane cost in Idaho this winter?
Nobody publishes a Idaho forecast; applying EIA’s September STEO national changes (+35% oil, -5% propane) to Idaho’s last-winter $3.94 and $2.36 per gallon gives roughly $5.30 and $2.25 — the ’this winter’ column. Idaho’s weekly SHOPP readings resume in October; the Winter Fuels Outlook (October 6) adds household expenditure on top.
Where do the Idaho prices on this page come from?
12.38¢/kWh is the EIA Electric Power Monthly average for Idaho over the October 2025–March 2026 editions (13.73¢ in July 2026); the share of homes on each heating fuel is Census ACS 2019–2023 5-year table B25040; $7.30/Mcf is the Natural Gas Monthly winter average (6 months), converted at 10.38 therms per Mcf; oil $3.94 and propane $2.36 per gallon are SHOPP season averages, regional or national where marked; degree-days are the STEO Mountain series. Only the ’this winter’ column is an estimate.
How we calculated this
Worked for Idaho at last winter’s averages: gas 10 × $0.70 ÷ 0.95 = $7.37/MMBtu; propane 10 × ($2.36 ÷ 0.91452) ÷ 0.92 = $28.09; oil 10 × ($3.94 ÷ 1.385) ÷ 0.85 = $33.47; resistance 293.07 × 0.1238 = $36.28; heat pump $36.28 ÷ 2.17 = $16.72. The this-winter column multiplies each by EIA’s national STEO change for that fuel (electricity ×1.026, gas ×0.903, propane ×0.953, oil ×1.345).Sources: U.S. Energy Information Administration (EIA) electricity rates · DSIRE incentive records · public IRS/OBBBA guidance. Figures are modeled estimates, not quotes or tax advice. See our methodology.
Where to go next
- Winter heating cost hub: gas vs propane vs oil vs electric — The national table, the arithmetic behind every row here, and all {len(COLD)} state pages.
- Gas vs heat pump heating cost — The COP a heat pump needs to beat gas at $0.70/therm.
- Propane vs heat pump cost — Propane at $2.36/gal against a heat pump at 12.38¢/kWh.
- Electric vs gas heat cost — Resistance heat versus gas across every state with a published gas price.
- Propane vs electric heat cost — Propane at $2.36/gal against resistance strips at 12.38¢/kWh.
- Heating oil and propane prices by state (weekly tracker) — Every SHOPP weekly reading behind Idaho’s oil and propane figures, with season lows, highs and trend lines.
- Heat pump crossover temperature — Seven named NEEP units at 12.38¢ and $0.70/therm — Idaho needs COP 4.92 to beat gas.
- Dual-fuel switchover calculator — Turns Idaho’s balance point (above 47°F (COP 4.92 needed against 3.20 available)) into a thermostat changeover setting.
- Heat pump sizing estimator — Idaho sits in IECC zone 6B; a January mean near 39°F is the design context for capacity.
- Why is my electric bill so high? — Splits a Idaho bill jump into weather (3,138 degree-days last winter), rate and usage.
- Solar panel cost in Idaho — The same 13.73¢/kWh July rate driving payback, utilities and rate history for Idaho.
- Cost to run a space heater in Idaho — 1,500 W at Idaho’s winter rate and degree-days — the per-hour and per-winter figure for one room.
- Cost to run a heat pump in Idaho — 3,500 W at Idaho’s winter rate and degree-days — the per-hour and per-winter figure for one room.
- Cost to run a ductless mini-split in Idaho — 2,000 W at Idaho’s winter rate and degree-days — the per-hour and per-winter figure for one room.
- Cost to heat a home in New York — Cold-state neighbour on this list: cheapest heat there was natural gas at $18.42/MMBtu.
- Cost to heat a home in Michigan — Cold-state neighbour on this list: cheapest heat there was natural gas at $11.05/MMBtu.