Grams to Milligrams converter (g to mg)
Convert Grams (g) to Milligrams (mg) with this free calculator. Type a value, press Convert, and the page applies the same factor shown in the formula below — no rounded shortcut, and nothing is stored on a server.
How to convert Grams to Milligrams
1 gram (g) is equal to 1000 milligrams (mg).
1 g = 1000 mg
The mass m in milligrams (mg) is equal to the mass m in grams (g) multiplied by 1000:
Example: Convert 5 g to milligrams:
m(mg) = 5 g × 1000 = 5000 mg
What is a Grams?
The gram (g) is one-thousandth of a kilogram. Nutrition labels, lab samples, and jewelry masses are commonly listed in grams.
What is a Milligrams?
The milligram (mg) is one-thousandth of a gram. Medicine doses and trace lab measurements are typically written in milligrams.
This page converts mass from Grams into Milligrams. One g equals 1000 mg.
Grams to Milligrams conversion table
Common g values and the matching mg result, calculated with the same factor as the widget. Highlight a nearby row if you want a quick check without entering a number.
| Grams (g) | Milligrams (mg) |
|---|---|
| 0 g | 0 mg |
| 0.1 g | 100 mg |
| 1 g | 1000 mg |
| 2 g | 2000 mg |
| 3 g | 3000 mg |
| 4 g | 4000 mg |
| 5 g | 5000 mg |
| 6 g | 6000 mg |
| 7 g | 7000 mg |
| 8 g | 8000 mg |
| 9 g | 9000 mg |
| 10 g | 10000 mg |
| 20 g | 20000 mg |
| 30 g | 30000 mg |
| 40 g | 40000 mg |
| 50 g | 50000 mg |
| 60 g | 60000 mg |
| 70 g | 70000 mg |
| 80 g | 80000 mg |
| 90 g | 90000 mg |
| 100 g | 100000 mg |
| 1000 g | 1000000 mg |
How this calculator works
The form on this page is a Grams-to-Milligrams converter. After you enter a number, JavaScript multiplies or rearranges it with the published conversion factor and writes the mg result in the output box. The step-by-step panel repeats the arithmetic so you can copy it into homework or a spreadsheet.
Reviewed by Hamsen, founder of GigaTables and a biology engineer. See the about page for how formulas are checked before a tool is published.
FAQ
How many mg are in 1 g?
1 g = 1000 mg.
How do I convert Grams to Milligrams?
The mass m in milligrams (mg) is equal to the mass m in grams (g) multiplied by 1000:
Is this g to mg converter free?
Yes. GigaTables calculators are free to use in a browser. You do not need an account, and the values you type are not uploaded.