Why Unit Conversion Matters
From international online shopping and cooking recipes to fitness tracking and real estate — the need for unit conversion comes up more often than you might think. While Korea officially uses the metric system (SI units), content from the US and UK still widely uses the imperial system.
Length Conversion: Centimeters, Inches, Feet, Miles
Here are the most commonly used length conversion relationships.
| Metric | Imperial | Factor |
|---|
| 1 cm | 0.3937 inches | ×0.3937 |
| 1 m | 3.2808 feet | ×3.2808 |
| 1 km | 0.6214 miles | ×0.6214 |
| 1 inch | 2.54 cm | ×2.54 |
| 1 foot | 30.48 cm | ×30.48 |
| 1 mile | 1.6093 km | ×1.6093 |
The "inches" used for TV and monitor sizes refer to diagonal length. A 55-inch TV measures approximately 139.7 cm diagonally.
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Length Converter
Instantly convert cm, inches, feet, miles, and more
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Weight Conversion: Kilograms, Pounds, Ounces
Knowing weight units precisely is essential for calculating shipping costs when shopping internationally.
| Metric | Imperial | Factor |
|---|
| 1 kg | 2.2046 pounds (lb) | ×2.2046 |
| 1 g | 0.0353 ounces (oz) | ×0.0353 |
| 1 pound | 453.59 g | ×453.59 |
| 1 ounce | 28.35 g | ×28.35 |
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Weight Converter
Quick conversion between kg, pounds, and ounces
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Temperature Conversion: Celsius and Fahrenheit
The conversion formulas between Celsius (°C) and Fahrenheit (°F) are:
°F = °C × 9/5 + 32
°C = (°F − 32) × 5/9
72°F on a US weather app equals about 22.2°C — a comfortable room temperature. Normal body temperature of 98.6°F equals 37°C.
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Temperature Converter
Instantly convert between Celsius and Fahrenheit
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Volume Conversion: Liters, Gallons, Cups
These volume units appear frequently in cooking recipes.
| Metric | Imperial | Factor |
|---|
| 1 liter (L) | 0.2642 gallons | ×0.2642 |
| 1 mL | 0.0338 fl oz | ×0.0338 |
| 1 gallon | 3.7854 L | ×3.7854 |
| 1 cup (US) | 236.59 mL | ×236.59 |
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Volume Converter
Convert liters, gallons, cups, and more
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Area Conversion: Square Meters, Pyeong, Acres
In Korean real estate, the traditional unit "pyeong" is still commonly used despite the official standard being square meters (m²).
- 1 pyeong = 3.3058 m² (approx. 35.58 ft²)
- 1 acre = 4,046.86 m² (approx. 1,224 pyeong)
- 1 hectare = 10,000 m² (approx. 3,025 pyeong)
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Pyeong Calculator
Convert between pyeong, m², and ft²
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Area Converter
Convert m², acres, hectares, and more
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Unit Conversion Tips
- Quick mental math: Remember 1 inch ≈ 2.5 cm, 1 pound ≈ 450 g, 1 mile ≈ 1.6 km for fast estimates.
- Cooking: In US recipes, 1 cup = about 240 mL, 1 tablespoon = about 15 mL.
- Exercise: To convert treadmill speed from mph to km/h, multiply by 1.6.