The metric ladder, weight, temperature, household measures, and time formats on one printable page.
| 1 g | = | 1,000 mg | gram to milligram |
| 1 mg | = | 1,000 mcg | milligram to microgram |
| 1 kg | = | 1,000 g | kilogram to gram |
| 1 L | = | 1,000 mL | liter to milliliter |
Every step on this ladder is a factor of 1,000, so moving between neighbouring units just moves the decimal point three places: right when you go to the smaller unit, left when you go to the larger one.
Worked example
0.25 g → mg: move the decimal 3 places right = 250 mg
250 mg → g: move the decimal 3 places left = 0.25 g
| 1 lb | = | 0.45359237 kg | exact, by definition |
| 1 kg | = | 2.2046 lb | 2.20462262…, rounded |
| 1 kg | ≈ | 2.2 lb | the common teaching value |
The pound is defined as exactly 0.45359237 kg, which makes 1 kg = 2.20462262… lb. Nursing programs commonly teach and accept the rounded 2.2, and the two routes give slightly different answers. Use whichever figure your program or facility specifies.
Worked example, both directions
154 lb → kg: 154 × 0.45359237 = 69.85 kg (with 2.2: 154 ÷ 2.2 = 70.0 kg)
70 kg → lb: 70 × 2.2046 = 154.3 lb (with 2.2: 70 × 2.2 = 154 lb)
| °F | = | (°C × 9/5) + 32 | Celsius to Fahrenheit |
| °C | = | (°F − 32) × 5/9 | Fahrenheit to Celsius |
Worked example
38.0 °C → °F: 38.0 × 9/5 = 68.4, then + 32 = 100.4 °F
100.4 °F → °C: 100.4 − 32 = 68.4, then × 5/9 = 38.0 °C
These are the taught conventions, rounded for easy mental math, not exact unit definitions. A US fluid ounce is 29.5735 mL, a US cup is 236.588 mL, and an ounce by weight is 28.3495 g. The rounded figures below are what nursing programs use.
| 1 tsp | = | 5 mL | teaspoon |
| 1 tbsp | = | 15 mL | tablespoon, 3 tsp |
| 1 fl oz | = | 30 mL | fluid ounce, 2 tbsp |
| 1 cup | = | 240 mL | 8 fl oz |
| 1 oz | = | 30 g | ounce by weight |
Minutes are unchanged in both formats. For the math and any time in between, use the Military Time Converter.
The mcg and mg step is where the thousand-fold errors live. Both units sit one rung apart on the same ladder, their abbreviations look alike in handwriting, and a decimal point dropped or gained three places changes an amount by a factor of a thousand, so it is worth reading that one step twice.
Rounded and exact factors disagree on purpose. Converting 154 lb with 2.2 gives 70.0 kg; converting it with the exact factor gives 69.85 kg. Neither is a mistake. Match whichever one your program, textbook, or facility asks for, and be consistent within a single problem.
Print it small. This page is laid out to fall onto one sheet in two columns, with the site chrome and the notes below dropped, so it fits a binder or folds into a badge pocket.
The metric relationships and the temperature formulas are definitional arithmetic. The pound is defined as exactly 0.45359237 kg per the international yard and pound agreement, as published by NIST; the 2.2046 and 2.2 values on this card are that same figure rounded. The household measures are the rounded values conventionally taught in nursing programs, listed here alongside their exact counterparts so the difference is visible.