Gas Furnace Replacement Cost by Size (2026)
| Furnace Size (Input BTU) | Pairs With | Typical Installed | 2026 Range (standard tier) |
|---|---|---|---|
| 40,000 - 60,000 BTU | 1.5 - 2 ton coil | $4,200 | $3,700 - $4,700 |
| 60,000 - 80,000 BTU | 2.5 ton coil | $4,400 | $3,900 - $5,000 |
| 80,000 BTU | 3 ton coil | $4,700 | $4,100 - $5,200 |
| 80,000 - 100,000 BTU | 3.5 ton coil | $4,900 | $4,300 - $5,500 |
| 100,000 BTU | 4 ton coil | $5,100 | $4,500 - $5,700 |
| 120,000 BTU | 5 ton coil | $5,600 | $4,900 - $6,200 |
All figures are installed prices at the standard tier (80% AFUE single-stage) and national-average labor - equipment, labor, permit, and disposal of the old furnace. Not sure which input-BTU size your home needs? Run the numbers through the furnace size calculator first - paying to install an oversized furnace is the most common (and most expensive) mistake in heating quotes.
Electric Furnace Cost vs Gas (2026)
Switch the fuel selector above to Electric and the price drops noticeably. That is not a trick of the calculator: an electric furnace genuinely costs less to put in, because there is no flue to run, no gas line to bring in, no combustion air supply and no gas permit. It is a cabinet of heating elements and a blower.
| Size | Electric furnace | Gas furnace | Upfront saving |
|---|---|---|---|
| 60,000 BTU | $2,300 - $2,900 | $3,700 - $4,700 | ~$1,400 |
| 80,000 BTU | $2,600 - $3,200 | $4,100 - $5,200 | ~$1,500 |
| 100,000 BTU | $2,800 - $3,600 | $4,500 - $5,700 | ~$1,700 |
| 120,000 BTU | $3,100 - $3,900 | $4,900 - $6,200 | ~$1,800 |
Now the part that matters more than the purchase price. Electric furnace cost is lower to install and roughly three times higher to run at typical US rates, because resistance heat buys you one unit of heat per unit of electricity while gas delivers the same heat far more cheaply per BTU. That $1,500 saving is recovered by the utility company inside a couple of winters in a cold climate, and never in a warm one where you barely run it.
So electric makes sense in three situations and rarely otherwise: there is no gas at the street and bringing it in costs thousands, the climate is mild enough that annual heating hours are low, or the furnace is a backup element behind a heat pump doing most of the work. If you are going all-electric by choice, a heat pump beats a resistance furnace by roughly two thirds on running cost and is the better place to put the money. The full running-cost arithmetic, with the break-even electricity rate, is on the furnace size calculator.
Furnace Installation Cost Estimate: What's Included in an Installed Price
A furnace installation cost estimate should always cover four things: the equipment itself, labor (typically a one-day job for a like-for-like swap), the mechanical permit, and haul-away of the old unit. What moves the number beyond that is scope. Reusing existing gas line, venting, and ductwork keeps you in the base ranges above. A first-time installation - or a fuel switch - adds gas-line work and flue or PVC venting. And ductwork is the biggest wildcard of all: sealing and minor modifications add about $2,000, while a full duct replacement adds $6,500 or more. Select the matching ductwork condition in the calculator to see your total with those line items included.
Efficiency tier is the other lever. Stepping an 80,000 BTU furnace from 80% AFUE single-stage to a 96% AFUE two-stage model moves the installed price from about $4,100-$5,200 to $4,900-$6,200; a modulating 97%+ unit runs $5,900-$7,600. Cold-climate homes usually earn that premium back in fuel savings; mild-winter homes often don't.
Furnace Replacement Cost Estimator vs a Contractor's Written Estimate
Worth knowing before you collect a single furnace replacement estimate: an estimate and a quote are not the same document, and contractors use the words loosely. An estimate is a considered guess that can move once someone opens up your ductwork. A quote, sometimes called a firm bid, is a price the contractor is agreeing to hold. Ask which one you are being handed, because the answer decides whether the number on the paper is the number you pay.
A furnace installation cost estimate is only comparable to another one if it lists the same things. Before you put two side by side, check that each shows the specific model number and its AFUE, the input BTU size and what that size was based on, whether a permit and inspection are included, whether hauling the old unit away is included, and any code work the installer expects to trigger, which is usually venting, gas line sizing, or the electrical disconnect.
The gap between what this estimator returns and what a contractor writes down is almost always one of those line items rather than the furnace itself. Two bids on identical equipment can sit $2,000 apart because one includes a new liner for the chimney and the other has quietly left it out.
The decision rule: compare the line items, never the bottom line. The cheapest total on the pile is frequently the one with the least written on it, and everything missing from the page reappears later as a change order.
Why Furnace Quotes Range from $3,000 to $10,000+ for the Same House
Collect three furnace quotes and you'll likely see numbers that differ by thousands for essentially the same job - and the equipment is rarely the reason. The biggest driver is company overhead: contractors who publish their pricing on camera quote entry-level single-stage installs anywhere from about $3,000-$4,900 at lean operations to $6,000-$8,000 at large fleet companies with showrooms and ad budgets - and homeowners regularly report paying under $3,000 at small two-truck shops. The furnace inside is often the same tier.
The rest of the spread comes from brand positioning (premium labels run 10-20% over mid-tier for similar hardware), scope add-ons (ductwork, a new gas line, venting changes, or bundled air-quality upgrades), and region. This calculator prices a mid-tier brand at your selected labor market (every constant is published in our cost model methodology), so treat it as the fair-price anchor: quotes far below it deserve a scope check (what's missing?), and quotes far above it deserve an overhead question (what am I paying for?). Get at least one bid from a smaller local operator alongside the big names, and before signing anything check what's left in 2026 HVAC rebates and tax credits - the federal 25C credit is gone, but utility and state programs still knock real money off high-efficiency furnaces.
Furnace Repair Cost Calculator: Repair or Replace?
Before pricing a replacement, sanity-check the repair route with the $5,000 rule: multiply the repair quote by your furnace's age in years - over $5,000, replace; under, repair. The two furnace repairs that most often trigger replacement:
| Repair | 2026 Cost | Note |
|---|---|---|
| Blower motor | $450 - $1,500 | variable-speed motors at the high end |
| Furnace heat exchanger | $2,000 - $3,500 | usually means replace the furnace |
Smaller fixes - igniters, flame sensors, control boards - usually favor repair on any furnace under 12-15 years old. Need the AC side too? See the full 2026 repair-price table covering capacitors, coils, and compressors.
Replacing the AC Too?
If your air conditioner is a similar age, price the combined job before committing to a furnace-only swap - doing both at once saves about 10% through shared labor and a single permit. The furnace and AC replacement cost calculator prices full combo systems, heat pumps, and mini splits, and the central air installation cost calculator handles AC-only jobs. This calculator, like all our tools, is pure math - no lead forms, no contractor callback, just the number you need before collecting quotes.