Area
—
Calculate area from length times width — mix units freely (like 10 ft × 60 in), add waste allowance for material shopping, and estimate total cost.
For a rectangle, area equals length multiplied by width: Area = Length × Width. The one rule that matters: convert both measurements to the same unit before multiplying — you can't multiply feet by inches directly and get a meaningful answer. Once they match, the result is automatically in square units: feet × feet = square feet, meters × meters = square meters, and so on. This calculator does the unit-matching for you, so you can enter each measurement in whatever unit you actually measured it in.
| Scenario | Length | Width | Area |
|---|---|---|---|
| A standard bedroom | 12 ft | 10 ft | 120 sq ft |
| A small room, metric | 4 m | 3 m | 12 m² |
| Mixed units | 10 ft | 60 in | 50 sq ft |
| Flooring with 10% waste | 120 sq ft room | 132 sq ft to buy | |
Linear: 12 in = 1 ft · 3 ft = 1 yd · 100 cm = 1 m · 1,000 m = 1 km · 2.54 cm = 1 in · 1 m ≈ 3.28084 ft
Area: 1 sq ft = 144 sq in · 1 sq yd = 9 sq ft · 1 m² ≈ 10.7639 sq ft · 1 acre = 43,560 sq ft · 1 hectare = 10,000 m²
Length times width is the formula for finding the area of a rectangle: multiply how long it is by how wide it is. The result is always in square units, since you're covering a two-dimensional surface.
Yes, for a rectangle (or square), length times width IS the area. This is the standard formula used for rooms, yards, tiles, fabric, and any other flat rectangular surface.
Convert them to the same unit before multiplying. This calculator does that automatically — enter 10 ft for length and 60 in for width, and it converts the inches to feet (5 ft) before multiplying, so you still get a correct area in square feet.
Because you're multiplying two one-dimensional lengths together, the result covers a two-dimensional area — mathematically, unit × unit = unit², which is why feet × feet gives square feet, not just feet.
Measure the length and width in feet, then multiply them together. If your measurements are in inches, divide by 12 first to convert to feet, or just enter them in inches here and the calculator converts automatically.
Measure the length and width in meters, then multiply them together. If you measured in centimeters, divide by 100 first, or enter centimeters directly here and let the calculator handle the conversion.
A common rule of thumb is 10% extra for waste, cuts, and mistakes — more (15%) for diagonal patterns or irregular rooms, less (5%) for very simple, rectangular layouts. Use the waste allowance option above to see the adjusted total.
Area is the amount of surface inside a shape (in square units) — how much flooring or paint you'd need. Perimeter is the total distance around the outside edge (in linear units) — how much fencing or trim you'd need.
Yes — enter a price per square foot or square meter in the cost section, and the calculator multiplies it by your (waste-adjusted) total area to estimate the material cost.
Yes — for larger areas, open "View all conversions" and check the acres or hectares figures, which are the standard units for land, gardens, and lots.