Convert stones to grams, kilograms, and total pounds, and enter mixed weights like 11 st 4 lb without extra math.
Table of contents
How to use our Stones to Grams Converter
- Choose "Stones only" if you have a whole or decimal number of stones, or choose "Stones and pounds" if your weight is written like 11 st 4 lb.
- Enter your value in "Stones (st)" and, if needed, enter leftover pounds in "Extra pounds (lb)".
- Pick "Round result to" if you want the gram result shown with a specific number of decimal places.
- Click "Calculate" to see "Grams", "Kilograms", "Total pounds", and "How it was worked out".
- Sanity-check the result by confirming that "Total pounds" equals stones times 14, plus any "Extra pounds (lb)" you entered.
Definitions
Stone (st): A UK weight unit equal to 14 pounds.[1]
Extra pounds (lb): Leftover pounds added after the whole stones, such as the 4 lb in 11 st 4 lb.
Grams (g): The main converted metric weight. There are 1,000 grams in 1 kilogram.
Kilograms (kg): A larger metric weight unit, often easier to read than grams for body weight.
Total pounds (lb): The full weight in pounds after converting all stones and adding any extra pounds.
Round result to: How many digits appear after the decimal point in the displayed gram result.
Common mistakes and quick fixes
Mistake: Typing leftover pounds into "Stones (st)" when your weight is really split, like 11 st 4 lb.
Fix: Switch "What are you converting?" to "Stones and pounds", enter 11 in "Stones (st)", and 4 in "Extra pounds (lb)".
Mistake: Entering 14 or more in "Extra pounds (lb)".
Fix: Move each full group of 14 pounds into "Stones (st)" and leave only the remainder in "Extra pounds (lb)".
Mistake: Leaving "Stones (st)" blank or typing text instead of a number.
Fix: Enter a numeric value in "Stones (st)", such as 10, 10.5, or 0 when you are also using "Extra pounds (lb)".
Mistake: Using "Stones only" but expecting "Extra pounds (lb)" to be included.
Fix: Choose "Stones and pounds" whenever you need the pounds part included in "Grams", "Kilograms", and "Total pounds".
Mistake: Thinking a very rounded "Grams" value means the exact result was zero or a whole number.
Fix: Change "Round result to" to more decimal places and check "How it was worked out" for the exact conversion math.
Limitations & Key Assumptions / Boundary Conditions
- This converter uses the standard relationship 1 stone = 14 pounds and converts through kilograms and grams using fixed unit definitions.
- In "Stones and pounds" mode, "Extra pounds (lb)" must be 0 or more and less than 14. Full groups of 14 pounds should be carried into "Stones (st)".
- In "Stones only" mode, the calculation ignores "Extra pounds (lb)" completely.
- The displayed "Grams" value is rounded to the number of decimal places you choose, so copied results may differ slightly from the full raw value.
- Very small positive inputs can round to 0 in the main display when low rounding is selected, even though the unrounded result is still above 0.
- This is a unit conversion tool only. It does not estimate health status, clothing size, or shipping rules.
Methodology
Conversion method
The calculator converts stones to grams using the exact chain 1 stone = 14 pounds[1] and 1 pound = 0.45359237 kilogram, so 1 stone = 6.35029318 kilograms = 6350.29318 grams.
grams = stones x 6350.29318
grams = (stones + pounds_extra / 14) x 6350.29318
pounds_total = stones x 14 + pounds_extra
kilograms = grams / 1000
Worked mini-example
For 11 st 4 lb, first turn the extra pounds into part of a stone: 4 / 14 = 0.2857142857 stone. Then add that to 11 to get 11.2857142857 stone. Multiply by 6350.29318 to get 71,214.0327885714 grams. That is 71.2140327886 kilograms, and the total pounds check is 11 x 14 + 4 = 158 pounds.
How to read the outputs
Grams is the main answer for forms, labels, recipes, or lab-style metric entries. Kilograms is the same weight in a shorter metric unit. Total pounds helps you verify that the mixed entry was combined correctly. How it was worked out shows whether the calculator used stones alone or stones plus extra pounds.
Calculation choices
If you choose "Stones only," the calculator uses only the "Stones (st)" value. If you choose "Stones and pounds," it adds "Extra pounds (lb)" as a fraction of a stone before converting. Display rounding changes how the shown answer looks, but not the underlying conversion.
Assumptions and limits
The method assumes standard avoirdupois weight units and fixed conversion factors. It does not accept 14 or more as "Extra pounds (lb)" because those full pounds belong in the stone part. Negative weights, blank required inputs, and non-numeric entries are treated as input errors rather than converted values.