Naúrar zafi kalori ne (wanda aka taƙaita kal). kalori shine adadin zafi da ake buƙata don ɗaga zafin gram 1 na ruwa da 1 Co (daidai daga 14,5 oC ya zama 15,5 oC). Adadin zafi da ake buƙata ya bambanta ga kowanne zafin jiki ruwa daban-daban. Don irin wannan adadin zafi, ƙara zafin ruwa na 1Co Yana faruwa ne kawai tsakanin zafin jiki na 14,5 oC zuwa 15,5 oC. Nau'in zafi da ake amfani da shi akai-akai, musamman don bayyana ƙimar kuzarin abinci, shine kilocalories (kcal). 1 kcal = kalori 1000. Wani suna na 1 kcal = kalori 1 (babban K). Nau'in zafi na tsarin Burtaniya shine Btu (naúrar zafi ta Burtaniya). 1 Btu = adadin zafi da ake buƙata don ɗaga zafin fam 1 na ruwa da 1 Fo (Daidai daga shafi na 63 oF ya zama 64 oF).
Zafi yana da alaƙa da makamashi, don haka muna buƙatar fahimtar alaƙar da ke tsakanin na'urorin zafi da na'urorin makamashi. Dangane da gwaje-gwajen da Joule da sauran masana kimiyya suka gudanar, an gano cewa Joules 4,186 na aiki daidai yake da kalori 1 na zafi.
Kalori 1 = Joules 4,186
1 kcal = kalori 1000 = Joules 4186
1 Btu = 778 ft.lb = 252 kalori = 1055 Joules
(Kalori 1 = 4,186 Joules kuma 1 kcal = 4186 ana kiransa zafi na inji)
Misali na tambayar wutar lantarki ta injina
1. 2 kcal (kilocalories) = ….. kalori?
Tattaunawa
1 kcal = kalori 1000
2 kcal = 2 (kalori 1000) = kalori 2000
2. Kalori 4 = ….. kalori?
Tattaunawa
Kalori 1 (babban adadin K) = kcal 1 = kalori 1000
Kalori 4 = 4 (kalori 1000) = kalori 4000
3. Kalori 10 = ….. Joules?
Tattaunawa
Kalori 1 = Joules 4,186
Kalori 10 = 10 (4,186 Joules) = Joules 41,86
4. 5 kcal = ….. Jimilla?
Tattaunawa
1 kcal = kalori 1000 = Joules 4186
5 kcal = 5 (4186 Joules) = 20930 Joules
5. Jimillar 2000 = ….. kcal ?
Tattaunawa
4186 Joules = 1 kcal
Jimillar 8372 = 8372 / 4186 = 2 kcal
Jimillar 2000 = 2000 / 4186 = 0,4777 kcal
