Measurement & Conversion Calculators

Why Measurement & Conversion Calculators Come First

Almost every estimate starts with area. Flooring, paint, gravel, and concrete all trace back to a square footage. Measurement & Conversion Calculators get that number right, then turn it into the unit a supplier, lender, or planner wants.

A small unit error grows fast. Mixing up square feet and square yards is a factor of nine. Mixing up area and volume can throw an order off completely.

Conversion Factors to Keep

These factors come from the exact definition of the foot, which is 0.3048 meters. They hold everywhere.

Area factors are squares of length factors. A yard is 3 feet, so a square yard is 3 × 3, or 9 square feet. A cubic yard is 3 × 3 × 3, or 27 cubic feet.

Finding Area

The Square Footage Calculator handles rooms and common shapes. The Square Yard Calculator gives the same area in yards, the unit carpet and some turf is sold in. The Square Meter Calculator gives metric area for imported products and plans drawn in meters.

Split odd rooms into simple shapes. Take an L-shaped room. One part is 12 ft by 10 ft, which is 120 sq ft. The other part is 6 ft by 8 ft, which is 48 sq ft. The total is 168 sq ft.

To convert, divide square feet by 9 for square yards. A 12 ft by 15 ft room is 180 sq ft, or 20 sq yd. Divide square feet by 10.764 for square meters.

Measuring Tips

Measure wall to wall at floor level. Walls are rarely perfectly straight, so take two readings and use the larger one. Round each measurement up to the next inch.

Convert inches to decimal feet before you multiply. Ten feet six inches is 10.5 ft, not 10.6 ft.

From Area to Volume

Bulk materials are sold by the cubic yard. The Cubic Yard Calculator works from length, width, and depth. The Square Feet to Cubic Yards Calculator starts from an area you already know.

When depth is in inches, one short formula does the job.

$$\text{Cubic yards} = \frac{\text{Square feet} \times \text{Depth (in)}}{324}$$

The 324 comes from 27 cubic feet times 12 inches per foot. A 600 sq ft area filled 4 inches deep needs 600 × 4 ÷ 324. That is about 7.41 cubic yards.

Add waste or compaction on top of the result. Different materials need different allowances.

From Area to Coverage

The Gallons per Square Foot Calculator links liquid volume to surface area. It helps with coatings, sealers, and water application.

One US gallon holds 231 cubic inches. Spread over 100 sq ft, that gallon makes a layer about 0.016 in thick. Coating makers call that 16 mils.

That leads to a handy coating formula.

$$\text{Wet mils} = \frac{1604}{\text{Coverage (sq ft per gallon)}}$$

A product spread at 400 sq ft per gallon goes on about 4 mils wet. Check the product label for its recommended coverage. Rough or porous surfaces soak up more.

From Area to Cost

The Cost Per Square Foot Calculator divides total cost by area. A $360,000 project with 2,400 sq ft works out to $150 per square foot.

The number is only useful when the area means the same thing each time. One quote may use finished living space. Another may include a garage or porch. Compare quotes only when they measure the same area.

From Area to Zoning

The Floor Area Ratio Calculator checks how much building a lot allows. The American Planning Association describes floor area ratio as building floor area divided by lot area.

$$\text{FAR} = \frac{\text{Gross floor area}}{\text{Lot area}}$$

A lot of 2,500 sq ft with a FAR of 2.0 allows 5,000 sq ft of floor area. That area could be one tall building on part of the lot or a lower one covering more of it.

The calculator reports your proposed FAR, lot coverage, and remaining capacity in one run. It accepts lot size in acres and converts it to square feet. FAR is not the only limit, though. Height, setbacks, and parking rules can cap a project first.

Each zoning code decides what counts as floor area. Some leave out basements, parking, or stairwells. Use your local definition before comparing.

One Patio, Every Number

Here is how the tools work together on one job. Take a patio 16 ft by 20 ft.

Every row starts from the same 320 sq ft. If that first number is wrong, every order after it is wrong too.

Common Mistakes

Dividing by 3 instead of 9. There are 3 feet in a yard but 9 square feet in a square yard.

Mixing inches and feet. Convert every dimension to the same unit before multiplying.

Using diameter as radius. The circle formula needs the radius, which is half the diameter.

Comparing mismatched areas. Cost per square foot means little if two quotes measure different spaces.

FAQs

How many square feet are in a square yard?

Nine. A square yard is 3 ft by 3 ft.

How do I convert square feet to cubic yards?

Multiply square feet by depth in inches, then divide by 324.

How many square feet are in a square meter?

About 10.764 square feet.

How many cubic feet are in a cubic yard?

Twenty-seven. A cubic yard is 3 ft on each side.

How do I find the square footage of a circle?

Square the radius and multiply by pi. A 12 ft circle has a 6 ft radius, so its area is about 113 sq ft.

What does a FAR of 1.0 mean?

The building’s counted floor area can equal the lot area. On a 10,000 sq ft lot, that allows 10,000 sq ft of floor area.