Feet and Inches Calculator

What is a feet and inches calculator?

A feet and inches calculator takes a measurement written in the mixed imperial form — a whole number of feet plus a number of inches — and expresses it in several equivalent units at once. Heights, room dimensions, fabric lengths and lumber are very often quoted as something like “5 ft 6 in”, but for arithmetic, ordering materials or working in the metric system you usually need a single value. This calculator converts your feet-and-inches input into total inches, decimal feet, centimeters and meters in one step.

How does the calculator work?

The calculator relies on two exact definitions: one foot equals $12$ inches, and one inch equals exactly $2.54$ centimeters. From those two facts every other result follows directly.

If you enter $f$ feet and $i$ inches, the total number of inches is:

The same measurement expressed as decimal feet is:

To reach the metric units, the total inches are multiplied by $2.54$ to get centimeters, and divided by a further $100$ to get meters:

Either field may be left blank — an empty box is treated as zero — so you can enter inches alone or feet alone. Only when both fields are empty does the calculator show no result.

Worked example

Suppose a person’s height is $5$ feet $6$ inches. Working through the formulas above:

So $5$ ft $6$ in equals $66$ inches, $5.5$ feet, $167.64$ centimeters and about $1.68$ meters.

Practical notes

• The conversion to centimeters and meters is exact because the inch is defined as exactly $2.54$ cm; the only rounding you see is in how many decimal places are displayed.
• Decimal feet are handy for spreadsheets and CAD software, which prefer a single number over a feet-and-inches pair.
• Decimal inches are accepted too: entering $10.5$ inches works the same way as a whole number of inches.

Frequently asked questions

How many inches are in 5 feet 6 inches?

There are $66$ inches, since $12 \times 5 + 6 = 66$.

What is 5 feet 6 inches in centimeters?

It is $167.64$ cm, because $66$ inches multiplied by $2.54$ equals $167.64$.

How do I convert feet and inches to meters?

Convert the measurement to total inches, multiply by $2.54$ to get centimeters, then divide by $100$. For $5$ ft $6$ in this gives $1.6764$ m.