Unit Converter — Length, Weight, Area, Volume & Temperature
Jun 23, 2026
Ever been confused by a US recipe calling for '1 cup' when you only have a metric measuring jug? Or tried to figure out how much a package weighs after seeing its weight listed in 'lbs'? Maybe you needed to convert a floor plan from pyeong to square metres for an interior project? Unit conversion comes up more often than you'd expect in daily life — cooking, online shopping, travel, and home renovation all bring different measurement systems into play. This guide covers the most common conversions across length, weight, area, volume, and temperature, with exact reference values and a free tool you can use immediately.
Enter a number, pick your units — instant result. Free, no install, no sign-up.
Open Unit Converter →Common Unit Conversions at a Glance
Here are the reference values you'll reach for most often, organised by category. Bookmark this page or just use the converter when you need an exact result.
Length — Inches, cm, Feet
TV and monitor screen sizes, clothing measurements from overseas retailers, and tool specifications often come in imperial units.
- 1 inch = 2.54 cm — this is an exact, defined value. A 12-inch laptop screen is exactly 30.48 cm.
- 1 foot (ft) = 30.48 cm — one foot equals 12 inches. Heights like '5 ft 10 in' are common in the US and UK.
- 1 m = 100 cm ≈ 39.37 inches ≈ 3.281 feet
- 1 mile = 1.609 km — appears on US road signs and running apps.
Weight — Pounds, kg, and the Korean Geun
International shipping fees, grocery labels in the US, and traditional Korean market units all require weight conversions.
- 1 pound (lb) ≈ 0.4536 kg — if a package says '2.2 lbs', that's roughly 1 kg.
- 1 kg ≈ 2.205 lbs
- 1 geun (근) = 600 g — a traditional Korean unit still used at butcher shops and produce stalls. One geun of pork means 600 g.
- 1 ounce (oz) ≈ 28.35 g — used for food nutrition labels and precious metals.
Temperature — Celsius and Fahrenheit
US recipes state oven temperatures in ℉, and weather apps abroad often default to ℉.
- ℉ = ℃ × 9 ÷ 5 + 32
- ℃ = (℉ − 32) × 5 ÷ 9
- Key reference points: water boils at 100 ℃ = 212 ℉ / normal body temperature 37 ℃ = 98.6 ℉ / oven at 350 ℉ ≈ 177 ℃
Area — Pyeong and Square Metres
Korean real estate listings traditionally use pyeong (평); official documents and architectural plans use ㎡.
- 1 pyeong = 3.3058 ㎡ (exactly 400/121 ㎡ ≈ 3.30579…)
- 1 ㎡ ≈ 0.3025 pyeong
- Example: a 33-pyeong apartment ≈ 109.09 ㎡ / an 84 ㎡ apartment ≈ 25.4 pyeong
If you work with floor areas regularly, the Pyeong Calculator is a handy companion — enter width and height to get both ㎡ and pyeong at once.
Volume — Cups, ml, and Fluid Ounces
Recipe conversions and beverage labelling are the most common cases.
- 1 US cup = 236.6 ml
- 1 tablespoon (tbsp) = 15 ml
- 1 teaspoon (tsp) = 5 ml
- 1 fluid ounce (fl oz) = 29.57 ml
- 1 litre (L) = 1,000 ml ≈ 4.23 US cups
How to Convert — 2 Steps
- Choose a category — open the Unit Converter and select the category you need: length, weight, area, volume, or temperature.
- Enter the value — type the number and the result appears instantly. Copy it and you're done — no sign-up, no install required.
Quick Reference Table
| From | Equals | Notes |
|---|---|---|
| 1 inch | 2.54 cm | Exact value |
| 1 foot (ft) | 30.48 cm | = 12 inches |
| 1 pound (lb) | 0.4536 kg | ≈ 453.6 g |
| 1 geun (근) | 600 g | Korean traditional unit |
| ℉ → ℃ | (℉ − 32) × 5 ÷ 9 | 100 ℃ = 212 ℉ |
| 1 pyeong (평) | 3.3058 ㎡ | Real estate & interior |
| 1 US cup | 236.6 ml | Recipes |
Related Tool
Need to calculate floor area from room dimensions? The Pyeong Calculator lets you enter width and length to get the area in both ㎡ and pyeong simultaneously — useful when comparing apartments or planning furniture layouts.
Type a number, get the answer instantly. Free.
Convert Now →Frequently Asked Questions
Q. How many kg is exactly 1 pound?
1 pound (lb) is exactly 0.45359237 kg by international definition. For everyday use, 0.4536 kg is accurate enough. A handy shortcut: 2.2 lbs ≈ 1 kg.
Q. How many square metres is 1 pyeong?
1 pyeong equals exactly 400/121 ㎡ ≈ 3.3058 ㎡. So a 33-pyeong apartment is approximately 109.09 ㎡. Note that official Korean property documents always state area in ㎡.
Q. Is there a quick mental trick for Fahrenheit to Celsius?
Subtract 32 from the ℉ value and halve the result for a rough ℃ estimate. For example, 68 ℉ → (68 − 32) ÷ 2 = 18 ℃ (exact answer is 20 ℃). For precision, use the converter.
Q. Is '1 cup' the same everywhere?
No — a US cup is 236.6 ml, a Japanese cup is 200 ml, and an Australian cup is 250 ml. Always check which country a recipe comes from, and use the unit converter to standardise in ml when accuracy matters.