Decimal Feet Converter
Convert feet and inches to decimal feet (tenths of a foot) and meters. Survey rods, cut sheets, and machine-control readouts use decimal feet; tapes are often feet and inches. Use the chart below for common inch and tenth values, then enter a tape reading to get the exact result.
Enter your values, then press Calculate.
How to calculate
Enter whole feet and remaining inches from the tape or rod. Inches may be decimal (6.5). Inches of 12 or more are added in, not rejected, so 10 ft 18 in becomes 11.5 ft. For 10 inches alone, enter 0 ft and 10 in (0.8333 decimal feet). To convert decimal feet back to feet and inches, use the feet/inches converter.
Formula
Decimal feet = feet + inches ÷ 12. Tenths of a foot are decimal feet to one decimal place (0.1 ft = 1.2 in). Meters = decimal feet ÷ 3.280839895. Total inches = decimal feet × 12. Remaining inches from a decimal-foot value = fractional part × 12.
Common use cases
- Grade rod to decimal feet
- Inches to tenths of a foot
- Plan elevation vs tape
- Checking a cut sheet
- Converting architectural inches to civil decimal feet
Assumptions
- Decimal feet means total feet including the fraction: 10 ft 6 in = 10.5 ft.
- Inches convert as inches ÷ 12. Tenths of a foot are 0.1 ft = 1.2 in, not 1 in.
- Whole feet and leftover inches are split only after the inch-to-foot conversion.
- Zero is a valid length.
Limitations
- Does not convert slope chains, metric stationing, or rods without using the length unit selector.
- Does not round to a carpenter’s 1/16 in unless that is the leftover after ÷ 12.
- Does not replace a grade-rod target; it only converts the number you already have.
- Does not go from decimal feet to meters unless you pick that output path on the inverse tool.
Worked examples
10 ft 6 in
10 ft + 6/12 = 10.5 decimal feet. On a rod in tenths that is 10.5, not 10.6.
1. Add inch fraction of a foot
10 + 6 ÷ 12 = 10.5 ft
10 inches in decimal feet
1. Add inch fraction of a foot
0 + 10 ÷ 12 = 0.8333 ft
Decimal feet chart
Inches to decimal feet (inches ÷ 12): 1 in = 0.0833 ft; 2 in = 0.1667 ft; 3 in = 0.2500 ft; 4 in = 0.3333 ft; 6 in = 0.5000 ft; 8 in = 0.6667 ft; 9 in = 0.7500 ft; 10 in = 0.8333 ft; 12 in = 1.0000 ft. Tenths of a foot to inches (tenths × 1.2): 0.1 ft = 1.2 in; 0.2 ft = 2.4 in; 0.3 ft = 3.6 in; 0.5 ft = 6.0 in; 0.7 ft = 8.4 in; 0.8 ft = 9.6 in; 0.9 ft = 10.8 in. Enter any other tape reading in the calculator for the exact value.
Convert inches to tenths of a foot
Civil layout often calls decimal feet “tenths.” Tenths of a foot are not tenths of an inch. 0.1 ft is 1.2 in, not 0.1 in. To convert inches to tenths, divide by 12 and read one decimal place, or enter the inches here and use the decimal-feet result. Example: 10 in = 0.8333 ft, which rounds to 0.8 ft (eight tenths) on a grade rod that only shows tenths.
Convert decimal feet back to feet and inches
This page turns a feet-and-inches tape reading into decimal feet. To go the other way, keep the whole feet and multiply the leftover decimal by 12 to get remaining inches, or open the feet/inches converter and enter the decimal-foot length. That related calculator is the reverse of this one; it does not change the formula used here.
Tenths of a foot on a grade rod
A rod marked in tenths is not a ruler in inches. 0.1 ft = 1.2 in, so 10.5 ft is 10 ft 6 in, and 0.8 ft is 9.6 in, not 8 in. If a cut sheet says 0.35 ft, that is 4.2 in. The inverse converter (feet/inches) starts from decimal feet and splits whole feet from remaining inches using the same identity.
Related calculators
- Feet/Inches ConverterConvert a length in any unit into feet and remaining inches.
- Station Difference CalculatorFind the distance between two stations in the 100-foot stationing system.
- Elevation Difference CalculatorFind the cut or fill between two elevations, in feet and inches.
- Pipe Slope CalculatorConvert elevation drop and run into percent grade, ratio, and inches per foot.
FAQ
Is 6 inches exactly 0.5 ft?
Yes. 6 ÷ 12 = 0.5. Use decimal inches (for example 6.125) when the tape shows a fraction.
When should I use decimal feet?
Cut sheets, grade rods, and most civil software store elevations as decimal feet. Convert the tape reading here, then take it to the instrument.
What is 10 inches in decimal feet?
10 in ÷ 12 = 0.8333 decimal feet (0.8 ft when rounded to tenths). Enter 0 ft and 10 in in the calculator for the live result.
How do I convert inches to tenths of a foot?
Divide inches by 12. One tenth of a foot is 0.1 ft, which is 1.2 in. Two tenths are 2.4 in. Enter the inch value here; the decimal-feet output is the tenth (or hundredth) value used on most grade rods.
How do I convert decimal feet back to inches?
Multiply the fractional part of the decimal-foot value by 12. Example: 10.5 ft → 0.5 × 12 = 6 in, so 10 ft 6 in. The feet/inches converter does that split from decimal feet, meters, yards, or inches.
Is there a decimal feet chart on this page?
Yes. The decimal feet chart below lists common inches-to-decimal-feet values and tenths of a foot in inches. It uses the same divide-by-12 formula as the calculator; it is not a separate table of nominal pipe or survey codes.
Why is 1.2 inches one tenth of a foot?
One foot is 12 inches, so 0.1 × 12 = 1.2 in. Treating a tenth as one inch is a common layout error of 20%.
Disclaimer
These calculators are estimating tools for planning and field checks. They are not a substitute for approved plans, specifications, licensed professional engineering, or governing standards. Confirm densities, waste factors, and yields with your supplier and project documents.