How we build the estimates

Comfort Math treats every result as a planning estimate. A useful calculator should expose its assumptions, validate its inputs, and explain what a browser cannot know about a house.

Data and assumptions

Each calculator keeps its rates and multipliers in a separate calculation module. Interface code does not contain pricing logic. This makes the model easier to test and update when the underlying data changes.

Ranges instead of false precision

HVAC quotes vary by equipment, location, access, permits, and contractor scope. We show rounded low, typical, and high values. A result such as $12,350.42 would imply accuracy the inputs cannot support.

Review schedule

Cost assumptions should be checked at least twice a year. Technical formulas should be reviewed whenever their referenced standard changes. Every production calculator will display its last review date and source notes.

Corrections

If an assumption is wrong or stale, we will correct the calculation module, add a regression test, and update the review date. The design keeps that process separate from page copy and presentation code.