What every result keeps visible
- Formula ID, version, reviewed status and planning boundary.
- Inputs, assumptions, allowance and purchase-rounding effect.
- Editable estimate costs that remain distinct from material quantity.
starter set · 2 tools in hvac
HVAC calculators
Planning furnace BTU and room CFM from floor area, ceiling height and a stated factor or air-change rate. Not Manual J, Manual D or an equipment size.
Formula-first tool library
Choose the right hvac calculator.
Furnace BTU calculator
Planning heating load from floor area, ceiling height and a stated BTU per square foot. Not Manual J.
Open calculatorCFM calculator
Planning airflow from room volume and air changes per hour. Not a duct design or Manual D.
Open calculatorCommon question
Is this Manual J or a furnace size?
These are transparent planning aids, not engineering, code, installation or final supplier specifications. Confirm actual job requirements before construction.