This free lb to stone conversion calculator makes it easy to switch between pounds and stones, whether you're tracking body weight, planning portion sizes, or reading a UK-based fitness or nutrition guide. The stone is still the standard unit for personal weight in the United Kingdom and Ireland, while pounds are commonly used in the US and in gym and food settings.
Simply enter a weight in pounds, choose how many decimal places you'd like, and press Convert. You'll receive the result as decimal stones, a full stones-and-remaining-pounds breakdown, and the equivalent mass in kilograms. That makes it useful for nutritionists, dietitians, personal trainers, and anyone comparing health numbers across different measurement systems.
No sign-up, no ads, just a clean and accurate conversion tool.
⚖️ lb to Stone Converter
Convert a weight in pounds to stones, stone-and-pound notation, and kilograms.
How to Use This Converter
Type or paste a weight in pounds into the input field, or tap one of the quick pick values below the field. Choose how many decimal places you want in your result, then press the Convert button. You can also press the Enter key while typing in the input field, which is handy when you are checking several weights in a row.
The calculator displays three useful views of the same weight: a decimal number of stones, the traditional UK style of whole stones plus remaining pounds, and the equivalent mass in kilograms. Use the Copy result button to copy the main conversion line to your clipboard, and Reset to clear everything and start again.
The Math Behind It
The stone is an imperial unit of mass defined as exactly 14 pounds avoirdupois. The international avoirdupois pound, in turn, is defined as exactly 0.45359237 kilograms, which means one stone is exactly 6.35029318 kg. These exact definitions make lb to stone conversions fully reliable for medical records, nutrition plans, and sporting data.
To convert pounds to stones, divide the number of pounds by 14. To convert pounds to kilograms, multiply by 0.45359237. If you need the traditional stones-and-pounds format, divide the total pounds by 14, take the integer part as whole stones, and keep the remainder as pounds. This is the same calculation used by doctors and fitness professionals in the UK.
Worked Examples
Example 1: 154 lb
154 ÷ 14 = 11 st, so 154 lb = 11 st exactly.
In kilograms: 154 × 0.45359237 ≈ 69.85 kg.
Example 2: 168 lb
168 ÷ 14 = 12 st, so 168 lb = 12 st exactly.
In kilograms: 168 × 0.45359237 ≈ 76.20 kg.
Example 3: 175 lb
175 ÷ 14 = 12.5 st. As whole stones and pounds, this is 12 st 7 lb because 12 × 14 = 168 and 175 − 168 = 7.
In kilograms: 175 × 0.45359237 ≈ 79.38 kg.
Example 4: 187 lb
187 ÷ 14 = 13.3571 st. The whole-stone part is 13 st, and 13 × 14 = 182, so the remainder is 5 lb. Therefore 187 lb = 13 st 5 lb.
In kilograms: 187 × 0.45359237 ≈ 84.82 kg.
Reference Data
The table below shows some common weights converted to decimal stones, stone-and-pound notation, and kilograms. It is useful for quickly checking whether your own result looks reasonable.
| Pounds | Stones (decimal) | Stones + lb | Kilograms |
|---|---|---|---|
| 140 lb | 10.00 st | 10 st 0 lb | 63.50 kg |
| 147 lb | 10.50 st | 10 st 7 lb | 66.68 kg |
| 154 lb | 11.00 st | 11 st 0 lb | 69.85 kg |
| 168 lb | 12.00 st | 12 st 0 lb | 76.20 kg |
| 175 lb | 12.50 st | 12 st 7 lb | 79.38 kg |
| 196 lb | 14.00 st | 14 st 0 lb | 88.90 kg |
Common Mistakes to Avoid
- Confusing decimal stones with stones-and-pounds. For example, 12.5 st means 12 st 7 lb, not 12 st 5 lb. The decimal part of the stone value must be multiplied by 14 to find the remaining pounds.
- Applying the conversion in reverse. To convert stones back to pounds, multiply by 14. A weight of 10 st is 140 lb, not 0.714 lb.
- Rounding too early. If you are using the result for a medical record or a precise nutrition target, keep the full precision until the final step. Rounding 175 lb to 12.5 st before converting to kilograms can introduce unnecessary error.
- Forgetting that values above 14 lb still produce whole stones. A weight like 30 lb is 2 st 2 lb, not just 2 st. The calculator handles this automatically, but it is a common manual error.
Precision Notes
The conversion factor of 14 lb per stone is exact, and the pound-to-kilogram factor of 0.45359237 is exact by international agreement. Any rounding only comes from the number of decimal places you select. At 0 decimal places, a weight of 149 lb will display as 10 st even though the true value is 10.64 st. For nutrition logs, training diaries, or comparing metric and imperial health data, 1 or 2 decimal places gives a better balance of readability and accuracy.
If your weight is written with ounces, such as 150 lb 8 oz, convert the ounces to pounds first by dividing by 16, add that to the pound value, and then use this calculator. The result will be accurate to the nearest ounce.
Frequently Asked Questions
Is 1 stone exactly 14 lb?
Yes. In the imperial system, one stone is legally defined as exactly 14 pounds avoirdupois. You can verify the definition in the Wikipedia article on the stone (unit).
Why is stone still used?
Personal body weight in the UK and Ireland is still commonly stated in stones and pounds, especially in medical settings, sports, and everyday conversation. Most people there understand their weight in stones far better than in kilograms.
How do I read a result like 12.5 st?
Take the integer part, 12 st, then multiply the decimal part by 14: 0.5 × 14 = 7 lb. So 12.5 st is exactly 12 st 7 lb.
Can I convert kilograms to stones here?
For that direction, try the kg to stone calculator, which works the other way and also gives stone-and-pound output.
What if my weight includes ounces?
Divide the ounces by 16 to get a decimal number of pounds, add it to the whole pound value, and enter that total. The calculator will then give the correct stone and kilogram equivalents.
The lb to stone conversion calculator is a practical companion for meal plans, training logs, health records, and everyday weight conversations wherever imperial pounds and UK-style stones meet.