How unit conversion works
Within each category, every unit is defined relative to a single base unit. Lengths are stored in meters, weights in grams, volumes in liters, and so on. Converting is then a two-step process: turn your value into the base unit, then turn the base unit into the target.
Result = Value × (factor of source ÷ factor of target)
For example, to convert 5 kilometers to miles, the tool multiplies by 1000 to reach meters, then divides by 1609.344 to reach miles — giving about 3.11 miles.
Temperature is a special case
Temperature scales don't share a zero point, so they can't use a single multiplier. Instead the converter applies the standard formulas:
- °C → °F: °F = °C × 9/5 + 32
- °F → °C: °C = (°F − 32) × 5/9
- °C → K: K = °C + 273.15
Common conversion factors
| From | To | Multiply by |
|---|---|---|
| Inches | Centimeters | 2.54 |
| Feet | Meters | 0.3048 |
| Miles | Kilometers | 1.609344 |
| Pounds | Kilograms | 0.453592 |
| Ounces | Grams | 28.3495 |
| Gallons (US) | Liters | 3.78541 |
Frequently asked questions
How does the unit converter work?
Every unit in a category is defined relative to one base unit — for example, all lengths are stored in meters. To convert, the tool turns your input into the base unit, then into the unit you want. Temperature is handled with its own formulas because the scales do not share a zero point.
How do you convert Celsius to Fahrenheit?
Multiply the Celsius value by 9/5 and add 32: °F = °C × 9/5 + 32. So 20 °C is 20 × 1.8 + 32 = 68 °F. To go the other way, subtract 32 first, then multiply by 5/9.
How many feet are in a meter?
One meter equals about 3.28084 feet, and one foot is exactly 0.3048 meters. The converter uses these exact factors, so a 5-meter length comes out as roughly 16.4 feet.
What is the difference between US and metric units?
Metric (SI) units — meters, kilograms, liters — scale by powers of ten, which makes conversions within the system simple. US customary units (feet, pounds, gallons) come from older systems with irregular ratios. This tool bridges the two so you can move between them without memorizing the factors.
Are the conversions exact?
The underlying factors are exact or to high precision, and results are rounded for readability. For length, weight, and volume the values are precise enough for everyday and most technical use; for legal or scientific work, always confirm against an authoritative standard.
Disclaimer: Results are rounded for readability and intended for everyday and general technical use. For legal, medical, or scientific work, confirm against an authoritative reference.