HVAC Replacement Cost Calculator

The budgeting rule of thumb is 1 ton per ~500 sq ft in hot climates (Phoenix, Houston), ~600 sq ft in mixed climates and ~700 sq ft where heating dominates — so a 2,000 sq ft home lands at 3–3.5 tons. It's a sizing guide, not a design: a proper Manual J load calculation (reputable installers run one before quoting) can move the answer a half-ton either way based on insulation, window area, orientation and air leakage.

The federal minimum since 2023 is 14.3 SEER2 in the North and 15.2 SEER2 in the South/Southwest. Stepping up to 16–17 SEER2 adds roughly 10% to equipment cost and 18–20 SEER2 about 22%. In long cooling seasons (Texas, Florida, Arizona) the electricity savings commonly repay the step-up in 4–7 years; in short-season northern climates the payback often outlives ownership, and the money is usually better spent on furnace quality or duct sealing.

Usually yes once both are past ~12 years. They share the blower and coil, mismatched pairings lose rated capacity and void most warranties, and the R-410A-to-R-454B/R-32 refrigerant transition means an old R-410A coil can no longer be matched to a new condenser across refrigerant families. Replacing together also saves a second mobilization — often $1,000+ of duplicated labor and permit fees.

Budget about $1,650 for targeted modifications — adding returns, sealing, extending a trunk — and roughly $2.50 per sq ft of home for full replacement, about $5,000 on a 2,000 sq ft house. That's why HomeGuide's national data shows system-plus-new-ductwork projects running $7,000–$16,000 versus $5,000–$11,000 for a change-out on good ducts. Duct condition is the single biggest swing between quotes that look like they're for the same job.

Yes, in nearly every jurisdiction. Mechanical permits commonly run $100–$300 — Sacramento, for example, charges roughly $175–$214 for a change-out — and this calculator budgets $215. The inspection covers refrigerant handling, combustion venting and the electrical connection; an unpermitted swap can block a future home sale, void insurance claims and forfeit manufacturer warranty registration.

Two compounding shocks: the EPA refrigerant transition from R-410A to lower-GWP R-454B/R-32 added an estimated 10–20% to equipment prices as manufacturers retooled, and installation labor rates kept climbing. On top of that, bids for the same written scope routinely spread 20–35% between contractors — which is exactly the band this calculator shows as low/high.

Rooftop packaged units almost always need one, and tight side-yards or fully fenced lots sometimes do for a split condenser — the calculator carries a $1,200 lift allowance when you select it. That allowance is usually cheaper than the alternative: packaged units weigh several hundred pounds, and hand-maneuvering one up a ladder risks the unit, the roof and the crew. Ground-set equipment with reasonable access doesn't need a lift — a two-person crew slides condensers on dollies. If a lift is quoted, ask whether it's rental-plus-operator or a subcontracted line item so you can compare bids.

A like-for-like change-out on reusable ducts is one 6–10 hour day. Add a half day when the refrigerant line set is replaced, and plan 2–4 days when ducts are being replaced — the sheet-metal work, not the equipment, drives the schedule. The longer pole is usually equipment availability: since the R-454B/R-32 transition, specific tonnage-and-SEER2 pairings can sit on backorder for weeks, so confirm the exact model is in stock before signing anything. Rooftop crane days and permit inspections can each add a scheduling day depending on the jurisdiction.