How do I add feet and inches with fractions?

Enter each value's feet, inches, and fraction separately. This calculator handles the carrying automatically, like 13/16 plus 1/2 rolling over into a whole inch.

What's the smallest fraction this tool supports?

1/16", the standard resolution for framing and general construction layout.

Can I subtract a dimension instead of adding it?

Yes, use the subtract function the same way. It deducts the entered dimension from your running total.

Architectural Linear Dimension Calculator

Perform rapid running-log additions and subtractions for job site blueprints and manufacturing shop calculations.

Feet (')

Inches (")

Fraction (Top)

Fraction (Bottom)

Accumulated Calculation Totals

Architectural Format

0'-0"

Fractional Inches

Decimal Inches

0.0000 in

Decimal Feet (Engineering)

0.0000 ft

How to Calculate Architectural Fractions

Construction takeoffs often mix decimal measurements with fractional ones. To convert a decimal to the nearest 1/16", multiply the decimal part by 16 and round to the nearest whole number, that becomes your numerator over 16.

Worked Example

Say a wall calls out at 12'-6 3/8" and you need to subtract a 2'-11 1/2" door rough opening. Enter both as feet, inches, and fraction, and the running total updates to 9'-6 7/8", accurate to the nearest 1/16".

Common Mistakes

Mixing up the top and bottom fraction values when entering an odd fraction like 5/16.
Forgetting results round to the nearest 1/16", so they won't always match a decimal tape measure reading exactly.
Not double-checking a cumulative running total against the original drawing before cutting stock.

Frequently Asked Questions

How do I add feet and inches with fractions?: Enter each value's feet, inches, and fraction separately. This calculator handles the carrying automatically, like 13/16 plus 1/2 rolling over into a whole inch.
What's the smallest fraction this tool supports?: 1/16", the standard resolution for framing and general construction layout.
Can I subtract a dimension instead of adding it?: Yes, use the subtract function the same way. It deducts the entered dimension from your running total.

Disclaimer: This tool is provided for educational and informational purposes only. All calculations are mathematical approximations rounded to the nearest 1/16 inch and should not replace professional engineering, architectural drafting, or certified job site layouts. The accuracy of the outputs depends entirely on user inputs. The website owner accepts no liability or responsibility for errors, material waste, structural failure, or financial losses resulting from the use of this software. Always verify your dimensions against a physical tape measure or approved blueprints before cutting or fabrication.