Reference
Unit conversions
The conversions that come up when measuring, ordering and spreading, in both directions, with the factors the calculators use.
Every calculator on this site works in either feet and inches or metric and converts between them using the exact definitions below. One foot is exactly 0.3048 meters and one pound is exactly 0.45359237 kilograms. The factors in the tables are rounded for everyday use.
To use a table, multiply the amount you have by the factor in the row. To go the other way, use the row for the opposite direction, or divide.
Length
| From | To | Multiply by |
|---|---|---|
| Inches | Centimeters | 2.54 |
| Centimeters | Inches | 0.394 |
| Feet | Meters | 0.3048 |
| Meters | Feet | 3.281 |
| Yards | Meters | 0.914 |
| Meters | Yards | 1.094 |
| Inches | Feet | 0.0833 (or divide by 12) |
| Feet | Inches | 12 |
Remember that feet and inches are not decimal. 6 feet 9 inches is 6.75 feet, not 6.9. Our guide to tape measures and decimal feet has a full conversion table.
Area
| From | To | Multiply by |
|---|---|---|
| Square feet | Square meters | 0.0929 |
| Square meters | Square feet | 10.764 |
| Square yards | Square feet | 9 |
| Square feet | Square yards | 0.111 |
| Square yards | Square meters | 0.836 |
| Square meters | Square yards | 1.196 |
| Acres | Square feet | 43,560 |
| Acres | Square meters | 4,047 |
| Square inches | Square feet | 0.00694 (or divide by 144) |
A quarter-acre lot is 10,890 square feet, or about 1,012 square meters. Much of that is house, driveway and beds. The lawn on a quarter-acre lot is commonly 5,000 to 7,000 square feet.
Volume
| From | To | Multiply by |
|---|---|---|
| Cubic yards | Cubic feet | 27 |
| Cubic feet | Cubic yards | 0.037 |
| Cubic yards | Cubic meters | 0.765 |
| Cubic meters | Cubic yards | 1.308 |
| Cubic feet | Cubic meters | 0.0283 |
| Cubic meters | Cubic feet | 35.31 |
| Cubic feet | Liters | 28.32 |
| Liters | Cubic feet | 0.0353 |
| Cubic meters | Liters | 1,000 |
| Cubic yards | Liters | 764.6 |
| Cubic feet | US gallons | 7.48 |
| US gallons | Liters | 3.785 |
The shortcut for beds: area in square feet × depth in inches ÷ 324 = cubic yards. In metric: area in m² × depth in cm ÷ 100 = cubic meters.
Weight
| From | To | Multiply by |
|---|---|---|
| Pounds | Kilograms | 0.4536 |
| Kilograms | Pounds | 2.205 |
| US tons (2,000 lb) | Pounds | 2,000 |
| US tons | Metric tonnes | 0.907 |
| Metric tonnes (1,000 kg) | US tons | 1.102 |
| Metric tonnes | Pounds | 2,205 |
| Ounces | Grams | 28.35 |
A US ton and a metric tonne differ by about 10%. When a supplier quotes “tons”, it is worth knowing which they mean. In the United States it is almost always the 2,000 pound ton.
Density
Density is weight per volume. It is what turns a volume of stone into a weight to order.
| From | To | Multiply by |
|---|---|---|
| Pounds per cubic yard | Kilograms per cubic meter | 0.593 |
| Kilograms per cubic meter | Pounds per cubic yard | 1.686 |
| Pounds per cubic foot | Pounds per cubic yard | 27 |
| Pounds per cubic foot | Kilograms per cubic meter | 16.02 |
| US tons per cubic yard | Metric tonnes per cubic meter | 1.187 |
Application rates
Seed and fertilizer rates are given per 1,000 square feet in the US and per square meter or per 100 square meters elsewhere.
| From | To | Multiply by |
|---|---|---|
| Pounds per 1,000 sq ft | Grams per square meter | 4.88 |
| Grams per square meter | Pounds per 1,000 sq ft | 0.205 |
| Pounds per 1,000 sq ft | Kilograms per 100 m² | 0.488 |
| Pounds per 1,000 sq ft | Pounds per acre | 43.56 |
| Pounds per acre | Pounds per 1,000 sq ft | 0.023 |
| Cubic yards per 1,000 sq ft | Cubic meters per 100 m² | 0.823 |
So the common lawn rate of 1 pound of nitrogen per 1,000 square feet is about 5 grams per square meter, or about 44 pounds per acre.
Slope
Drainage slopes are stated three ways: as a fall per foot, as a percentage, or as a ratio.
| Fall per foot | Percent | Ratio | Fall over 10 ft |
|---|---|---|---|
| ⅛ in | 1.0% | 1 in 96 | 1¼ in |
| ¼ in | 2.1% | 1 in 48 | 2½ in |
| ½ in | 4.2% | 1 in 24 | 5 in |
| 1 in | 8.3% | 1 in 12 | 10 in |
Patios and paths are usually laid with a fall of ⅛ to ¼ inch per foot, away from buildings. To convert a fall in inches per foot to a percentage, divide by 12 and multiply by 100.
Lumber: nominal and actual sizes
Not a unit conversion in the strict sense, but the conversion that causes the most trouble.
| Sold as | Actual size |
|---|---|
| 1 × 4 | ¾ × 3½ in |
| 1 × 6 | ¾ × 5½ in |
| 5/4 × 6 | 1 × 5½ in |
| 2 × 4 | 1½ × 3½ in |
| 2 × 6 | 1½ × 5½ in |
| 2 × 8 | 1½ × 7¼ in |
| 2 × 10 | 1½ × 9¼ in |
| 2 × 12 | 1½ × 11¼ in |
| 4 × 4 | 3½ × 3½ in |
| 6 × 6 | 5½ × 5½ in |
Lengths, unlike widths, are true. An 8 foot board is 8 feet long, sometimes a fraction over.
Tables last reviewed October 4, 2026.