Length
Feet and inches into one inch count
Always perform this step before touching 2.54. Converting the two parts separately gives the wrong answer.
The Formula
total in = feet x 12 + inches
Always perform this step before touching 2.54. Converting the two parts separately gives the wrong answer.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| ft | Whole feet in the measurement | feet | Multiplied by 12, because a foot holds twelve inches rather than ten. |
| in | Leftover inches | inches | The remainder after whole feet. Never write this as a decimal fraction of a foot. |
| in_total | Total length in inches | inches | The single number that then gets multiplied by 2.54. |
What Each Symbol Means
ftfeet
Whole feet in the measurement
Multiplied by 12, because a foot holds twelve inches rather than ten.
ininches
Leftover inches
The remainder after whole feet. Never write this as a decimal fraction of a foot.
in_totalinches
Total length in inches
The single number that then gets multiplied by 2.54.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to convert inches to centimeters page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Convert Inches To Centimeters, filed under Unit Conversion. Every number the guide produces comes from substituting into this one line.