nmol/L to mg/dL Calculator
nmol/L counts particles, and mg/dL weighs them. Pick your substance to link the two.
Quick answer: Multiply the nmol/L by the molar mass, then divide by 10,000,000. For example, 100 nmol/L of Testosterone is 0.002884 mg/dL, 100 nmol/L of Vitamin D (25-OH D3) is 0.004006 mg/dL and 100 nmol/L of Iron is 0.000559 mg/dL.
The nmol/L to mg/dL formula
Molar concentration becomes mass concentration when you multiply by the molar mass (Wikipedia: Molar concentration).
A nmol/L times g per mol gives ng per liter. Then 1 ng per liter is 10 million times smaller than 1 mg/dL.
Take 100 nmol/L of Testosterone. 100 × 288.42 ÷ 10,000,000 gives 0.002884 mg/dL.
Take 100 nmol/L of Vitamin D (25-OH D3). 100 × 400.64 ÷ 10,000,000 gives 0.004006 mg/dL.
nmol/L to mg/dL by substance
Value in nmol/L.
Substance. It sets the molar mass.
mg/dL is the result. The last column gives the factor for 1 nmol/L.
How to convert nmol/L to mg/dL step by step
- Enter the value in nmol/L.
- Pick the substance, or enter its molar mass.
- Read the result in mg/dL.
- Check it against the quick table.
Example 1: 100 nmol/L of Testosterone
- Start with 100 nmol/L of Testosterone.
- 100 × 288.42 ÷ 10,000,000 = 0.002884.
- The concentration is 0.002884 mg/dL.
100 nmol/L of Testosterone = 0.002884 mg/dL
Example 2: 100 nmol/L of Vitamin D (25-OH D3)
- Start with 100 nmol/L of Vitamin D (25-OH D3).
- 100 × 400.64 ÷ 10,000,000 = 0.004006.
- The concentration is 0.004006 mg/dL.
100 nmol/L of Vitamin D (25-OH D3) = 0.004006 mg/dL
Example 3: 100 nmol/L of Iron
- Start with 100 nmol/L of Iron.
- 100 × 55.85 ÷ 10,000,000 = 0.000559.
- The concentration is 0.000559 mg/dL.
100 nmol/L of Iron = 0.000559 mg/dL
The big divisor of 10,000,000 comes from changing ng to mg and liters to deciliters. This page checks maths only. It is not medical advice, so ask your lab or clinician about any result or dose.
nmol/L to mg/dL conversion table
| Value and substance | mg/dL | Per 1 nmol/L |
|---|---|---|
| 100 nmol/L of Testosterone | 0.002884 mg/dL | 0.00002884 mg/dL per 1 nmol/L |
| 50 nmol/L of Vitamin D (25-OH D3) | 0.002003 mg/dL | 0.00004006 mg/dL per 1 nmol/L |
| 500 nmol/L of Iron | 0.002793 mg/dL | 0.00000559 mg/dL per 1 nmol/L |
| 1,000 nmol/L of Glucose | 0.018 mg/dL | 0.00001802 mg/dL per 1 nmol/L |
| 10 nmol/L of Cholesterol | 0.000387 mg/dL | 0.00003867 mg/dL per 1 nmol/L |
| 5,000 nmol/L of Triglycerides | 0.4427 mg/dL | 0.00008854 mg/dL per 1 nmol/L |
| 100 nmol/L of Creatinine | 0.001131 mg/dL | 0.00001131 mg/dL per 1 nmol/L |
| 50 nmol/L of Urea | 0.0003 mg/dL | 0.00000601 mg/dL per 1 nmol/L |
The highlighted row is the default of the calculator. The last column gives mg/dL per 1 nmol/L.
A quick mental shortcut for nmol/L to mg/dL
Divide the molar mass by 10 million for the factor.
So the answer is always a very small number for hormones.
What nmol/L measures
nmol/L means billionths of a mole in one liter of fluid (Wikipedia: Molar concentration).
Hormone and vitamin reports often use it.
What mg/dL measures
mg/dL means milligrams of a substance in one deciliter of fluid.
US reports use it for glucose and cholesterol.
Why the substance matters
A mole is a count of particles, and heavier particles weigh more for the same count (Wikipedia: Molar mass).
So the same nmol/L gives a different mg/dL for each substance.
Example: Testosterone
For Testosterone, the molar mass used is 288.42 g per mol.
So 100 nmol/L is 0.0028842 mg/dL.
Example: Vitamin D (25-OH D3)
For Vitamin D (25-OH D3), the molar mass used is 400.64 g per mol.
So 100 nmol/L is 0.0040064 mg/dL.
Example: Iron
For Iron, the molar mass used is 55.85 g per mol.
So 100 nmol/L is 0.0005585 mg/dL.
Your own substance
If your substance is not in the list, enter its own molar mass.
Find it on the product label or in a trusted reference table.
Going the other way
To go back, multiply the mg/dL by 10,000,000 and divide by the molar mass.
For Testosterone, 0.0028842 mg/dL goes back to 100 nmol/L.
Check your answer
Reverse the answer with the back formula.
For Testosterone, 0.0028842 mg/dL should return 100 nmol/L.
A worked example
20 nmol/L of testosterone, with a molar mass of 288.42 g/mol, is 0.000577 mg/dL.
Quick conversion answers
| Conversion | Result |
|---|---|
| 500 nmol/L of Vitamin D (25-OH D3) | 0.02 mg/dL |
| 1,000 nmol/L of Iron | 0.005585 mg/dL |
| 10 nmol/L of Glucose | 0.00018 mg/dL |
| 5,000 nmol/L of Cholesterol | 0.1933 mg/dL |
| 100 nmol/L of Triglycerides | 0.008854 mg/dL |
| 50 nmol/L of Creatinine | 0.000566 mg/dL |
Where this conversion is used
Many labs outside the US report hormones and vitamins in nmol/L.
US lab reports list blood values in mg/dL.
Common mistakes to avoid
- Using the wrong substance. Each substance has its own molar mass.
- Mixing up the direction. Here 500 nmol/L of Vitamin D (25-OH D3) is 0.02 mg/dL, so a correct answer comes out smaller than the number you start with.
- Mixing dL, L and mL. A liter is 10 deciliters and 1,000 mL.
- Rounding too early. The answer for 5,000 nmol/L of Cholesterol is 0.1933 mg/dL. Cut it to 0.19 mg/dL and you are off by about 1.7 percent, and the gap grows if you reuse it.
Related converters
Example: Glucose
For Glucose, the molar mass used is 180.16 g per mol.
So 50 nmol/L is 0.0009008 mg/dL.
Example: Cholesterol
For Cholesterol, the molar mass used is 386.65 g per mol.
So 500 nmol/L is 0.019333 mg/dL.
Frequently asked questions
How do I convert nmol/L to mg/dL?
mg/dL = nmol/L × molar mass ÷ 10,000,000.
Why does it depend on the substance?
Each substance has its own molar mass, so the factor changes.
How many mg/dL is 100 nmol/L of Testosterone?
0.0028842 mg/dL.
How many mg/dL is 100 nmol/L of Vitamin D (25-OH D3)?
0.0040064 mg/dL.
What if my substance is not listed?
Pick the custom option and enter its molar mass.
Is this medical advice?
No. It checks the maths only. Ask your lab or clinician about your result.
Sources
- Wikipedia: Molar concentration (en.wikipedia.org)
- Wikipedia: Mass concentration (chemistry) (en.wikipedia.org)
- Wikipedia: Molar mass (en.wikipedia.org)
