Furnace Cost Guide 2026

Quick Answer: A residential furnace commonly runs $1,500 to $4,500 per unit as of 2026 for the equipment itself, and $2,500 to $7,500 installed. Commercial furnaces and larger packaged units run higher, $4,000 to $12,000 per unit. The price is set mostly by capacity (BTU input), efficiency (AFUE), fuel type, and brand tier. Treat the ranges below as a planning anchor and pull live quotes from your supplier for the actual bid.

What Drives the Price

A furnace is the heat generating appliance in a forced air heating system, sized by input BTU per hour and rated by annual fuel utilization efficiency (AFUE). It is priced per unit, not per foot. Six variables drive almost all of the cost:

Capacity (BTU input): Residential furnaces run from 40,000 BTU (small apartment) to 120,000 BTU (large house). Commercial units run higher. Bigger capacity means a bigger heat exchanger, bigger blower, and more money. A 40,000 BTU unit is the cheapest in a line; a 120,000 BTU unit is the most expensive.
Efficiency (AFUE): AFUE measures how much of the fuel becomes usable heat. An 80 percent AFUE furnace wastes 20 percent up the flue. A 95 to 98 percent AFUE condensing furnace captures most of that waste. High efficiency units cost $800 to $2,000 more than standard efficiency in the same capacity, and they require PVC venting instead of a metal flue.
Fuel type: Natural gas is the most common and usually the cheapest equipment. Propane furnaces are nearly identical to gas but require a conversion kit and a tank. Oil furnaces are older technology, still common in the Northeast, and typically cost more for the equipment. Electric furnaces are cheapest to buy but cost the most to run in most markets.
Brand tier: Builder grade (basic efficiency, short warranty) is the cheapest. Mid tier adds better components and a longer warranty. Premium tier adds variable speed blowers, modulating gas valves, and 10 to 12 year parts warranties. Premium can be 50 to 100 percent over builder grade in the same capacity.
Configuration: Upflow, downflow, and horizontal units are the same price in the same model line. A horizontal unit for an attic or crawlspace may carry a small premium for the coil cabinet. A packaged unit (furnace and AC in one cabinet, roof or ground mounted) costs more than a split system furnace.
Stage of heating: Single stage is cheapest. Two stage is mid. Modulating is premium and gives the best temperature control and the highest efficiency. Modulating adds $500 to $1,500 over single stage.

Steel and copper commodity indexes move the equipment cost modestly, but brand pricing cycles and distributor stock have a bigger effect than the raw commodity on any given bid.

Typical Price Ranges by Type

These are commonly quoted ranges as of 2026, per unit, equipment only. Installed pricing includes labor, venting, sheet metal, and electrical and runs $1,000 to $3,000 higher than equipment only.

80 percent AFUE gas, 40,000 to 60,000 BTU, builder grade: $1,200 to $2,000
80 percent AFUE gas, 80,000 to 100,000 BTU, builder grade: $1,500 to $2,400
80 percent AFUE gas, 120,000 BTU, builder grade: $1,800 to $2,800
95 to 96 percent AFUE gas, 60,000 to 80,000 BTU, mid tier: $2,200 to $3,200
95 to 96 percent AFUE gas, 100,000 to 120,000 BTU, mid tier: $2,800 to $4,000
97 to 98 percent AFUE gas, modulating, mid tier: $3,200 to $4,500
97 to 98 percent AFUE gas, modulating, premium tier: $4,200 to $6,000
Oil furnace, 80,000 to 120,000 BTU: $2,400 to $4,000
Electric furnace, 10 kW to 20 kW: $1,000 to $2,000
Commercial packaged gas furnace, 100,000 to 200,000 BTU: $4,000 to $8,000
Commercial packaged gas furnace, 200,000 to 400,000 BTU: $6,000 to $12,000

How to Calculate the Quantity You Need

Furnaces are counted from the mechanical schedule, not measured by the foot. Read the equipment schedule on the mechanical sheets: each row is one furnace, with model, capacity, efficiency, and fuel. Count the rows, group by model, and price each group at the correct unit cost.

Apply a 0 percent waste factor. Furnaces are not cut or consumed on site. You buy exactly what the schedule calls for. The waste factor belongs on the ductwork, sheet metal, and venting lines, not on the equipment.

Round up to the buy unit, which is one furnace. If the schedule calls for three identical furnaces, price them at the three unit line, which may carry a small volume discount from the supplier. Do not round a partial furnace up; if the schedule says two, you price two.

Tie every furnace count to the schedule row it came from. When the GC asks where a number came from, you should be able to point at the equipment schedule and the floor it serves in seconds. If the schedule calls for a 95 percent AFUE unit and you priced an 80 percent unit, you eat the difference.

How to Buy Smarter

Pull three quotes on bid day. Brand pricing cycles twice a year and distributors carry different stock. A 15 to 30 percent spread between suppliers on the same model is normal, especially around the season change.
Match the model to the spec, not the price. If the spec calls for a 96 percent AFUE modulating furnace, do not substitute an 80 percent single stage to save money without a written RFI response. The wrong efficiency fails inspection and the energy code.
Bundle the HVAC package. Buying the furnace, AC condenser, coil, ductwork, and venting from one supplier in a negotiated package usually beats line item shopping, and it gives you one backorder to manage.
Lock the model, not just the price. A quote without a model number is a placeholder. Get the brand, model, and capacity in writing so the supplier cannot swap to a cheaper unit when you order.
Check the warranty tier. Builder grade units ship with a 5 year parts warranty. Mid and premium tier ship with 10 year parts, sometimes 20 year heat exchanger. The warranty tier affects the replacement cost over the life of the unit and the bid value, not just the day one price.

Where Estimators Get It Wrong

The most common mistake is pricing the wrong efficiency tier. The equipment schedule calls for a 96 percent AFUE furnace, the estimator prices an 80 percent unit because the model number looks close, and the bid is $1,000 low per furnace. Read the AFUE rating on the schedule, not just the brand.

The second is missing the venting conversion. A high efficiency furnace requires PVC venting instead of a metal flue, and a condensate drain. If you price the equipment and forget the PVC and drain, the install runs over.

The third is ignoring the electrical service. A modulating furnace with a variable speed blower draws more power than a single stage unit, and the electrical bid may need a larger circuit. Coordinate with the electrical takeoff.

The fourth is forgetting the coil cabinet. A furnace paired with an AC coil needs a matching coil cabinet, and the coil is a separate line item. Price the furnace and the coil together or the bid is short the coil.

Putting It Together

Price furnaces by the unit, off the equipment schedule, with the correct AFUE, capacity, fuel, and model for each row. Apply a 0 percent waste factor to the equipment and put the waste on the ductwork and venting lines. Reprice on bid day from three suppliers, lock the model number in writing, and bundle the furnace with the AC and ductwork package. Read the schedule for efficiency and venting requirements before you commit. The furnace is the largest single equipment line on the residential mechanical bid, so match the spec exactly.