Free home exterior calculators
3 free calculators for the outside of the house: siding squares with gables, openings and waste, a roof replacement estimate from footprint, pitch and material, and how much exterior paint to buy. Every factor is cited and every assumption labeled.
Updated · By the Interior Redesign AI editorial team · Sources cited on the page
Siding and paint
Squares and gallons for the walls.
Roof and cost
Roof area, squares and replacement cost.
How we calculate
Each tool does plain, visible arithmetic in your browser, with no AI and no server call, and shows its formula, a worked example and its sources on the page. Code figures cite the model code section, quantities cite the manufacturer's published spec, and prices cite a named cost guide with the date we checked it.
Where we had to assume something, the page says so and the widget lets you change it. Results are planning numbers, not quotes or code rulings.
More tools for this project
- House Color Visualizer · Body, trim, door and roof colors on a house.
- House Paint Visualizer · Preview exterior paint colors.
- Exterior Color Combinations · 50+ body, trim and door combos with paint codes.
- All free tools · kitchen, bathroom, paint, flooring, outdoor, exterior and room planning.
Then see it on your house
The same photo, before and after an AI render. Your walls, windows and layout stay; the finishes change.
Questions
Are these exterior calculators free?
Yes. They run in your browser, cost nothing and need no account. Only the AI redesign of your own house photo needs a free account.
Where do the numbers come from?
Roof pitch factors are geometry; coverage and waste come from manufacturer installation guides and paint data sheets; prices from named cost guides with the date we checked them.
Are the roof costs quotes?
No. They are planning ranges. Tear-off layers, decking repairs, flashing and local labor move real bids, so get at least three.