Free zoning calculation tool
Calculate existing and proposed lot coverage, compare it with a zoning limit, and see how much buildable footprint may remain.
Enter the project measurements, then select Calculate. Nothing is uploaded or stored.
How to use the calculator
Lot coverage normally measures the portion of a parcel occupied by building footprints. A city may count houses, garages, sheds, covered patios, pools or other features differently, so the local definition controls the final permit calculation.
Continue your permit planning
Calculation questions
These answers explain the planning calculation. Verify local definitions before using the result in a permit package.
No. Lot coverage uses ground-level building footprints. FAR compares the counted floor area on all levels with the lot area.
Some codes regulate building coverage and impervious coverage separately. A driveway may be excluded from building coverage but included in impervious coverage.
Check the zoning table for the property’s district or ask the city or county planning department. Do not rely on a general percentage from another jurisdiction.
The calculation is a planning estimate. A permit submission normally needs a scaled site plan showing the source dimensions and the jurisdiction’s required coverage table.
Need drawings, not just a calculation?
Send the property address, proposed project and any city checklist. We will confirm the drawing scope before you order.
Calculation methodology reviewed August 2026 · Educational planning tool, not a zoning determination or survey.
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