Enter your own budget for equipment, ductwork, installation/labor, and permits, plus a contingency percentage, to estimate a total.
How to Use the HVAC Cost Calculators
Fill in the four line items — equipment, ductwork, installation and labor, and permits — then set a contingency percentage. The subtotal and padded total update together as you edit any field.
HVAC projects split fairly cleanly into equipment cost and installation cost, and the two don't scale together the way people expect: a bigger, more efficient unit doesn't necessarily mean proportionally more labor, while ductwork replacement can cost more than the equipment itself in an older home with an undersized duct system.
Subtotal = Equipment + Ductwork + Installation & labor + Permits & inspection
Contingency = Subtotal × (Contingency % ÷ 100)
Total = Subtotal + ContingencyDuctwork Is the Line Item Most Often Underestimated
A straightforward equipment swap that reuses existing ducts is a much smaller job than one that also has to resize, reseal, or extend ductwork to a new layout. If your ducts haven't been inspected in years, budget that field higher than the equipment cost alone might suggest is necessary.
This is a rough planning tool, not a contractor quote. Correctly sizing HVAC equipment requires a load calculation specific to your home's square footage, insulation, and climate — get that done by a licensed contractor before buying equipment, since an oversized or undersized system wastes money either way.
Ten Percent Contingency Assumes Ducts Are Accessible
The default 10% buffer here is lighter than the 15% suggested for kitchens, since a like-for-like equipment swap tends to have fewer hidden surprises than tearing into cabinetry and plumbing. Raise it if your ductwork runs through finished walls or ceilings that would need to be opened up.