Room Area Calculator

Measure any room shape, convert units, and estimate materials instantly with confidence. Include tile waste, pricing, and multi-section plans for accurate bids every time.

Calculator Inputs
Choose a shape, enter dimensions, then estimate waste, tiles, and costs.
For irregular rooms, use sections for best accuracy.
Typical flooring allowance is 5–15%.

Select whether the value is radius or diameter.
Add both optional sides for perimeter.
Cut-out is removed from one corner.
Each section is a rectangle you measure separately.

Use the same unit selection above.
Example: USD, EUR, PKR.
Reset
Formula Used
All dimensions are converted to meters before calculations.
  • Rectangle: A = L × W, P = 2(L + W)
  • Square: A = s², P = 4s
  • Circle: A = πr², P = 2πr (if diameter is entered, r = d/2)
  • Triangle: A = ½bh (perimeter needs all three sides)
  • Trapezoid: A = ½(a + b)h (perimeter needs both non-parallel sides)
  • L-Shape: A = (OL×OW) − (CL×CW), P = 2(OL+OW) + 2(CL+CW)
  • Waste allowance: Aᵥ = A × (1 + w/100)
  • Tile count: N = ceil(Aᵥ / (tL×tW))
  • Cost: Cost = Aᵥ × price_per_m²
How to Use This Calculator
  1. Select your room shape and measurement unit.
  2. Enter the required dimensions for that shape.
  3. For irregular rooms, choose sectioned layout and add rectangles.
  4. Add waste percentage to match your installation method.
  5. Optional: enter tile size and price per square meter.
  6. Press Calculate to view results above the form.
  7. Use the download buttons to export CSV or PDF reports.
Example Data Table
Sample inputs and typical results for quick reference.
Example Shape Dimensions Area (m²) Area (ft²) Waste
1 Rectangle 5 m × 4 m 20.00 215.28 8%
2 Circle Radius 2 m 12.57 135.32 10%
3 L-Shape Outer 7×6 m, Cut 3×2 m 36.00 387.50 12%
Room Area Planning Guide
A practical, professional overview to support takeoffs and estimates.

Why accurate room area matters

Accurate floor area prevents material shortages, avoids over-ordering, and improves bid confidence. A 2% measuring error on a 35 m² room changes purchases by 0.7 m², which can equal one extra box of tiles or planks.

Common measurement approaches

Most rooms are treated as rectangles, but alcoves, closets, and bay windows often create compound shapes. In practice, installers either compute an L-shape by subtracting a cut-out, or break the plan into measurable rectangles and sum them.

Shape formulas used in the calculator

The calculator applies standard geometry: rectangles use L×W, circles use πr², and trapezoids use ½(a+b)h. For perimeter, it uses 2(L+W) for rectangles and 2πr for circles when the necessary edge data is available.

Unit conversion and reporting

All inputs are converted to meters before calculation, then reported in m² and ft². The conversion factor is 1 m² = 10.7639 ft². This dual output helps when drawings are metric but products, quotes, or labor rates are in square feet.

Waste allowance and practical ranges

Waste accounts for cuts, breakage, pattern matching, and future repairs. Straight-lay installations often use 5–8%, while diagonal layouts, large-format tile, and rooms with many corners commonly need 10–15%. The calculator applies Aᵥ = A×(1+w/100).

Tile quantity estimation

Once a tile length and width are entered, tile area is computed and the count is rounded up using a ceiling rule. For example, 0.6 m × 0.6 m tiles cover 0.36 m² each. A 22 m² waste-adjusted area needs ceil(22/0.36)=62 tiles.

Cost planning for budgeting

Cost is calculated from waste-adjusted area because that is what you typically purchase. If a finish is priced at 15 per m² and the adjusted area is 22 m², the estimate becomes 330. Use this as a planning number, then confirm with supplier packaging and batch sizes.

Field tips for better accuracy

Measure along finished wall lines, note any permanent obstructions, and keep units consistent. For sectioned rooms, label each rectangle on a sketch to avoid double counting. Recheck any dimension that differs by more than 2 cm from your expected plan.

When estimating baseboards, use perimeter when available and subtract door widths. For paint, multiply wall perimeter by ceiling height, then remove large openings. These checks align takeoffs with real site conditions and crew workflows.

FAQs
Quick answers for common measurement and estimating questions.

1) Which shape should I choose for an irregular room?

Use the sectioned option and split the room into simple rectangles. Sum their areas for a reliable total. This mirrors how takeoffs are typically performed from plans and site sketches.

2) Why does the calculator show perimeter as unavailable sometimes?

Perimeter needs every outer edge length. Sectioned layouts and some shapes can’t determine shared walls or missing sides from area inputs alone, so the tool avoids guessing.

3) What waste percentage is reasonable for flooring?

Many straight-lay installs use 5–8%. Diagonal patterns, many corners, and brittle materials often require 10–15%. If you expect future repairs, consider ordering slightly higher.

4) How does tile quantity estimation work?

The tool divides waste-adjusted area by tile area and rounds up to the next whole tile. Rounding up accounts for cuts and packaging limits where partial tiles cannot be purchased.

5) Can I use this for paint estimation?

It provides floor area and sometimes perimeter. Paint usually needs wall area, which is perimeter multiplied by wall height, then reduced for doors and windows. Use the perimeter output as a starting point.

6) Why are results shown in both m² and ft²?

Projects often mix drawings and supplier units. Dual reporting reduces conversion errors and speeds quoting. The calculator uses a consistent conversion factor to keep takeoffs comparable.

7) How should I measure to improve accuracy?

Measure along finished wall lines, keep units consistent, and recheck outliers. For sectioned rooms, label each rectangle on a sketch to prevent overlap or missed alcoves.

Accurate room areas help budgets, bids, and beautiful finishes.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.