Milligrams to Grams Converter (mg to g)

How to convert milligrams to grams

To convert milligrams to grams, multiply the number of milligrams by 0.001 (or divide by 1,000).

Example: 500 mg = 0.5 g.

Medication and supplement doses are often listed in milligrams.

Milligrams to Grams conversion chart

mg	g
0.25 mg	0.00025 g
0.5 mg	0.0005 g
0.75 mg	0.00075 g
1 mg	0.001 g
1.5 mg	0.0015 g
2 mg	0.002 g
2.5 mg	0.0025 g
3 mg	0.003 g
3.5 mg	0.0035 g
4 mg	0.004 g
4.5 mg	0.0045 g
5 mg	0.005 g
6 mg	0.006 g
7 mg	0.007 g
8 mg	0.008 g
9 mg	0.009 g
10 mg	0.01 g
11 mg	0.011 g
12 mg	0.012 g
13 mg	0.013 g
14 mg	0.014 g
15 mg	0.015 g
16 mg	0.016 g
18 mg	0.018 g
20 mg	0.02 g
24 mg	0.024 g
25 mg	0.025 g
30 mg	0.03 g
32 mg	0.032 g
35 mg	0.035 g
40 mg	0.04 g
45 mg	0.045 g
50 mg	0.05 g
55 mg	0.055 g
60 mg	0.06 g
64 mg	0.064 g
65 mg	0.065 g
70 mg	0.07 g
75 mg	0.075 g
80 mg	0.08 g
85 mg	0.085 g
90 mg	0.09 g
100 mg	0.1 g
110 mg	0.11 g
120 mg	0.12 g
125 mg	0.125 g
128 mg	0.128 g
150 mg	0.15 g
175 mg	0.175 g
180 mg	0.18 g
200 mg	0.2 g
220 mg	0.22 g
250 mg	0.25 g
300 mg	0.3 g
400 mg	0.4 g
500 mg	0.5 g
750 mg	0.75 g
1,000 mg	1 g

Metric vs. U.S. customary units

The United States uses U.S. customary units — inches, feet, miles, pounds, gallons and degrees Fahrenheit — for most everyday purposes. Canada officially adopted the metric system in the 1970s, so road signs, weather forecasts, gas pumps and food labels use kilometers, degrees Celsius, liters and grams. In practice many Canadians still use feet and inches for height, pounds for body weight and square feet for homes, which is why conversions come up constantly on both sides of the border.

Exact conversion factors

Since 1959 the inch, foot, yard, mile and pound have been defined in metric terms, so these conversions are exact, not approximations:

1 inch = 2.54 cm exactly, so 1 foot = 30.48 cm and 1 mile = 1.609344 km.
1 pound = 0.45359237 kg exactly; 1 ounce = 28.349523125 g.
1 U.S. gallon = 3.785411784 liters. The imperial gallon used in the U.K. is larger: 4.54609 liters.
1 acre = 4,046.8564224 m², and 1 hectare = 10,000 m² (about 2.471 acres).

Temperature is different because the scales have different zero points: °F = °C × 9/5 + 32 and °C = (°F − 32) × 5/9. Water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F) at sea level, and −40 is the same in both scales.

Quick mental shortcuts

Kilometers to miles: multiply by 0.6 (100 km ≈ 60 miles; the exact figure is 62.1).
Kilograms to pounds: double it and add 10% (70 kg → 140 + 14 = 154 lb).
Celsius to Fahrenheit: double it and add 30 for a rough estimate (20 °C → 70 °F; the exact answer is 68 °F).
Liters to U.S. gallons: divide by 4 for a quick estimate (40 L ≈ 10 gallons; exactly 10.57).

Cooking and recipe conversions

U.S. recipes measure by volume — cups, tablespoons and teaspoons — while Canadian and most international recipes use milliliters and grams. A U.S. cup is about 237 mL, but Canadian "metric" measuring cups hold 250 mL, so the difference adds up in baking. For flour, sugar and butter, weighing in grams is more accurate than cups because the density of each ingredient differs.

Popular conversions

Pick a conversion below for a dedicated page with the formula, worked examples and a complete conversion chart.

Tips for accurate conversions

Keep full precision until the final step and round only the answer — rounding intermediate numbers can add noticeable errors, especially in recipes, construction and engineering. Always check which gallon, ounce or ton a source means: U.S. and imperial units share names but not sizes, and a "fluid ounce" measures volume while an "ounce" of weight measures mass. For temperatures, remember that a temperature difference converts differently from a temperature reading: a change of 10 °C equals a change of 18 °F, without adding 32.

Popular unit conversions

Frequently asked questions

How many centimeters are in an inch?

Exactly 2.54 centimeters. To convert inches to centimeters, multiply by 2.54; to convert centimeters to inches, divide by 2.54.

How do I convert kg to pounds?

Multiply kilograms by 2.20462. For example, 70 kg × 2.20462 = 154.3 lb.

What is the formula for Celsius to Fahrenheit?

Multiply by 9/5 (1.8) and add 32. For example, 25 °C × 1.8 + 32 = 77 °F.

Is a U.S. gallon the same as a Canadian gallon?

No. Canada sells gas by the liter, but when gallons are mentioned in Canada they are sometimes imperial gallons (4.546 L), which are about 20% larger than U.S. gallons (3.785 L).

How many square feet are in a square meter?

About 10.764 square feet. A 1,000 sq ft home is roughly 92.9 m².

Sources & methodology

This calculator was last reviewed on November 2, 2026. Figures are based on the following official and primary sources:

NIST – Handbook 44, Appendix C: General Tables of Units of Measurement

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