Interior measurement
Room Area Calculator
Find floor area, perimeter, and metric equivalents from room length and width.
Use this calculatorVisual home project planning
Measure smarter before you buy.
HomeMeasureKit helps DIY planners, renters, and homeowners turn room measurements into practical paint, wallpaper, moving box, curtain, rug, flooring, tile, room, and wall planning estimates with visible formulas, editable assumptions, and simple visuals.
- No login
- Feet, inches, and metric
- Formulas shown
Calculator workflow
Start with dimensions, then plan materials.
Start with room dimensions, then estimate paint gallons, wallpaper rolls, moving boxes, curtain panels, rug sizes, flooring boxes, tile counts, floor area, and wall area. Each live calculator opens directly and explains the assumptions behind the result.
Interior measurement
Wall Area Calculator
Estimate gross and net wall area after subtracting doors, windows, and custom openings.
Use this calculatorInterior measurement
Paint Calculator
Estimate paint gallons, coats, waste, and optional cost for a room.
Use this calculatorInterior measurement
Wallpaper Roll Calculator
Estimate wallpaper rolls while keeping repeat pattern and waste visible.
Use this calculatorFlooring and tile
Flooring Calculator
Estimate floor area, added waste, boxes needed, and optional cost.
Use this calculatorFlooring and tile
Tile Calculator
Estimate tile counts from project area, tile size, waste, and box quantity.
Use this calculatorFlooring and tile
Rug Size Planner
Compare room size and furniture layout to practical rug size ranges.
Use this calculatorWindows and decor
Curtain Panel Calculator
Estimate curtain panel width and length from window size and fullness.
Use this calculatorMoving and storage
Moving Box Calculator
Estimate moving boxes by room count, home size, and packing density.
Use this calculatorWorked project workflow
One room, several shopping decisions
A single set of room measurements can support several estimates, but each material needs a different formula and product assumption. This example is calculated with the same production functions used by the live tools.
Example room: 12 ft x 10 ft room with 8 ft walls, one 3 ft x 7 ft door, and two 3 ft x 5 ft windows
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Measure the floor
12 ft x 10 ft
120 sq ft of floor area
Check in the detailed calculator -
Separate gross walls from openings
352 sq ft gross - 51 sq ft openings
301 sq ft of net wall area
Check in the detailed calculator -
Estimate paint from the same measurements
301 sq ft x 2 coats + 10% waste at 350 sq ft per gallon
2 gallons to buy
Check in the detailed calculator -
Turn floor area into whole boxes
120 sq ft + 10% waste at 20 sq ft per box
7 flooring boxes to buy
Check in the detailed calculator
This is a worked planning example, not a purchase recommendation. Measure the actual room, replace the example coverage values with the selected product label, and review installation guidance before buying.
Transparent and user-first
Every estimate should explain itself.
Each calculator explains the formula, assumptions, examples, and limits behind the estimate.
What HomeMeasureKit avoids
HomeMeasureKit avoids electrical, gas, structural, legal, permit, loan, insurance, health, and other safety-critical calculators. Those areas require licensed professional judgment.
Calculator-first pages
Users can reach a working tool quickly, then read formula details when they need them.
Transparent assumptions
Waste factors, rounding, unit conversion, and limits are kept visible near the result.
Clear planning foundation
A clear calculator-first experience keeps inputs, results, and planning notes easy to follow.