Enter a decimal stone weight or whole stones plus extra pounds to find the full weight in pounds.
Advanced options
Table of contents
How to use our Stone to Pounds Converter
- Choose "Decimal stone" for one value such as 11.5 st, or choose "Whole stones plus pounds" for a value such as 11 st 4 lb.
- Enter the weight shown in the active field or fields. In mixed format, put the number before "st" in "Whole stones (st)" and the number before "lb" in "Extra pounds (lb)".
- Open "Advanced options" only if you need a different number of displayed decimal places.
- Click "Calculate" to see "Total pounds".
- Sanity-check a mixed entry: extra pounds must be from 0 through 13, because 14 lb equals one more stone.
Definitions
Stone (st): A unit of weight equal to exactly 14 pounds. [1]
Decimal stone: A stone weight written as one number, such as 11.5 st.
Mixed weight: A weight written with whole stones and leftover pounds, such as 11 st 4 lb.
Extra pounds: The pounds left after whole stones are counted. A normalized mixed weight has 0 through 13 extra pounds.
Total pounds: The complete entered weight expressed in pounds.
Common mistakes and quick fixes
Mistake: Entering 11 st 4 lb as 11.4 in "Stone (st)".
Fix: Choose "Whole stones plus pounds" and enter 11 whole stones and 4 extra pounds.
Mistake: Leaving out the pounds part of a mixed weight.
Fix: Enter the number after "lb" in "Extra pounds (lb)" so it is added to the converted stones.
Mistake: Entering 14 or more in "Extra pounds (lb)".
Fix: Turn each 14 lb into one whole stone. For example, 9 st 14 lb should be entered as 10 st 0 lb.
Mistake: Entering 2.5 in "Whole stones (st)".
Fix: Choose "Decimal stone" for 2.5 st, or use a whole number of stones with 0 through 13 extra pounds.
Mistake: Treating screen rounding as a change to the conversion.
Fix: Change "Result decimal places" if needed. The calculator uses the unrounded entered value before formatting the answer.
Limitations & Key Assumptions / Boundary Conditions
- This tool converts weight units only. It does not assess health, body composition, or a recommended weight.
- Mixed input accepts whole stones plus 0 through 13 extra pounds. Convert every 14 extra pounds into one additional stone before entering the value.
- Decimal and mixed notation are different: 11.4 st is not the same weight as 11 st 4 lb.
- Changing displayed decimal places changes only screen rounding, not the conversion calculation.
- Negative values, non-finite values, and mixed notation typed into the decimal-stone field are not accepted.
Methodology
Conversion method
One stone equals exactly 14 pounds. [1] For a decimal-stone entry, the calculator multiplies the entered value by 14.
Total pounds = decimal stone × 14
For a mixed weight, it converts the whole-stone part first, then adds the leftover pounds.
Total pounds = (whole stones × 14) + extra pounds
Worked example
For 9 st 3 lb, 9 × 14 = 126 lb, and 126 + 3 = 129 lb. For 11.5 st, 11.5 × 14 = 161 lb.
Display rounding
The calculator keeps the calculated total before formatting it. The "Result decimal places" setting changes the displayed number only.