UNDERSTAND THE METHOD
How to use this calculator
Select a conversion group and edit any unit field. Other units update from the full entered value. For a rectangle, enter the length and width using the selected unit. Volume and fuel economy use US liquid measures, not UK Imperial measures.
What the result can tell you
Conversions describe units, not interchangeable physical quantities. Ounces of weight differ from fluid ounces. Food label Calories mean kilocalories. US customary cups and US label cups are separate fields. The label cup is 240 mL; a customary cup is about 236.59 mL.
Common questions
Can I convert weight ounces to fluid ounces?
No direct conversion is possible because weight and volume measure different properties. A substance density is needed for that conversion.
Which cup and volume conventions does the converter use?
Volume and fuel-economy fields use US liquid measures. The label cup is 240 mL, while the US customary cup is about 236.59 mL; they are separate fields.
Sources & limitations
Sources checked September 12, 2026. These notes identify methods and assumptions. They have not received an independent clinical review.
How we check and update content