Free HVAC calculators
Quick, honest numbers for the truck or the proposal: balance points, heat loss and a first-pass load. They run in your browser, need no sign-up and show the formula behind every result.
- Free, no sign-up
- Runs in your browser
- Estimate: shows its formulas
Heat pump balance point calculator
Thermal and economic balance points, backup kW at design and a dual-fuel switchover, on a chart you can probe.
Open the calculatorHeat loss calculator
U × A × ΔT plus air leakage, room or whole house, with a component breakdown and design-temperature lookup.
Open the calculatorHVAC load calculator
A quick whole-house heating and cooling estimate from a handful of inputs. Clearly an estimate, not a Manual J.
Open the calculator
Every tool uses standard, published methods (ASHRAE Handbook—Fundamentals physics, ASHRAE design temperatures via Climate.OneBuilding.org) and gives an estimate. None of them is a Manual J or Manual S calculation.
The full load calculation, on an iPad
The tools give quick answers. calc.blue does the whole job: scan the house with LiDAR, get room-by-room heating and cooling loads with a likely range, size heat pumps and furnaces at the house's design temperatures, and hand out reports for the permit office, the installer and the homeowner.