Mass and weight aren't actually the same thing
Everyday speech treats them as interchangeable, but physics draws a sharp line: mass is how much matter an object contains, while weight is the force gravity exerts on that mass. A 10 kg object has a mass of 10 kg everywhere in the universe — on Earth, on the Moon, floating in deep space — but its weight changes dramatically depending on local gravity.
Benda seberat 10 kg itu memiliki berat sekitar 98 newton di Bumi dan kira-kira seperenam di Bulan, semata-mata karena gravitasi bulan lebih lemah — jumlah materi sebenarnya tidak berubah. Kalkulator ini sepenuhnya berfungsi dalam satuan massa (kg, lb, batu, ton); untuk sisi persamaan gaya yang bergantung pada gravitasi, itulah yang ditangani oleh konversi berat khusus.
Units that don't mean what they sound like
A few mass units carry hidden traps for anyone converting by hand:
| Satuan | Setara |
|---|---|
| 1 batu | 14 lb (6.35 kg) |
| 1 ton AS (pendek). | 2,000 lb (907.2 kg) |
| 1 metric ton (tonne) | 1,000 kg (2,204.6 lb) |
| 1 lb | 0.453592 kg |
Stone — still the everyday unit for body weight in the UK and Ireland — divides into 14-pound blocks rather than any round metric number, which is exactly why "11 stone 6" doesn't convert to a tidy kilogram figure without doing the arithmetic. And three completely different "tons" (US short ton, UK long ton, metric tonne) exist side by side, differing by as much as 10% from each other — worth double-checking on anything involving freight, shipping, or industrial quantities.
Why a gold ounce and a sugar ounce aren't the same size
The ounce you'd use to weigh flour (the avoirdupois ounce, about 28.35 g) is not the same ounce used to price gold, silver, or other precious metals (the troy ounce, about 31.1 g) — a nearly 10% difference. Precious metals have used the troy system since medieval trade fairs, and it's stuck around specifically in that industry ever since, which is why a "one ounce" gold coin is noticeably heavier than a one-ounce coin of ordinary metal would be under the everyday system.
Mass, density, and volume
Massa, massa jenis, dan volume dihubungkan dengan satu rumus — massa sama dengan massa jenis dikali volume — itulah sebabnya kalkulator ini dapat menyelesaikan salah satu dari ketiga rumus tersebut jika diberi dua rumus lainnya. Untuk mengetahui lebih dalam mengenai massa jenis itu sendiri, termasuk cara menggunakannya untuk mengidentifikasi material dan mengapa benda mengapung atau tenggelam, lihat Kalkulator Kepadatan. Dan jika Anda membutuhkan berat sebagai gaya, bukan massa – termasuk berapa berat suatu massa di planet lain – maka Kalkulator Beratmencakup itu.