Sodium conversion: blood sodium in mmol/L × 2.299 = mg/dL, and sodium mmol/L is the same number as mEq/L. For food and supplements, 1 mmol of sodium = 23 mg, so mg ÷ 23 = mmol. Example: serum sodium 140 mmol/L = 321.9 mg/dL = 140 mEq/L; 2,300 mg of sodium = 100 mmol.
Sodium (Na⁺) Calculator
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Sodium Conversion Factors (mmol/L, mg/dL, mEq/L, g/L)
Sodium (Na⁺) has an atomic mass of 22.99, which gives all the factors below.
| Convert sodium | Formula | Example |
|---|---|---|
| mmol/L to mg/dL | mg/dL = mmol/L × 2.299 | 140 mmol/L = 321.9 mg/dL |
| mg/dL to mmol/L | mmol/L = mg/dL ÷ 2.299 (or × 0.435) | 322 mg/dL = 140 mmol/L |
| mmol/L to mEq/L | mEq/L = mmol/L (sodium has a charge of 1) | 140 mmol/L = 140 mEq/L |
| mmol/L to g/L | g/L = mmol/L × 0.02299 | 140 mmol/L = 3.22 g/L |
| mg to mmol (amount) | mmol = mg ÷ 22.99 | 1,000 mg = 43.5 mmol |
| mmol to mg (amount) | mg = mmol × 22.99 | 100 mmol = 2,299 mg |
| sodium to salt (NaCl) | salt (g) = sodium (g) × 2.54 | 2.3 g sodium = 5.8 g salt |
Serum Sodium mmol/L to mg/dL Chart
Blood (serum) sodium is almost always reported in mmol/L or mEq/L, which are identical. Use this chart if you need mg/dL or g/L, for example for a research paper or an older reference.
| Sodium (mmol/L = mEq/L) | Sodium (mg/dL) | Sodium (g/L) |
|---|---|---|
| 115 mmol/L | 264.4 mg/dL | 2.64 g/L |
| 120 mmol/L | 275.9 mg/dL | 2.76 g/L |
| 125 mmol/L | 287.4 mg/dL | 2.87 g/L |
| 128 mmol/L | 294.3 mg/dL | 2.94 g/L |
| 130 mmol/L | 298.9 mg/dL | 2.99 g/L |
| 132 mmol/L | 303.5 mg/dL | 3.03 g/L |
| 134 mmol/L | 308.1 mg/dL | 3.08 g/L |
| 135 mmol/L | 310.4 mg/dL | 3.10 g/L |
| 136 mmol/L | 312.7 mg/dL | 3.13 g/L |
| 138 mmol/L | 317.3 mg/dL | 3.17 g/L |
| 140 mmol/L | 321.9 mg/dL | 3.22 g/L |
| 142 mmol/L | 326.5 mg/dL | 3.26 g/L |
| 144 mmol/L | 331.1 mg/dL | 3.31 g/L |
| 145 mmol/L | 333.4 mg/dL | 3.33 g/L |
| 146 mmol/L | 335.7 mg/dL | 3.36 g/L |
| 148 mmol/L | 340.3 mg/dL | 3.40 g/L |
| 150 mmol/L | 344.9 mg/dL | 3.45 g/L |
| 155 mmol/L | 356.3 mg/dL | 3.56 g/L |
| 160 mmol/L | 367.8 mg/dL | 3.68 g/L |
| 165 mmol/L | 379.3 mg/dL | 3.79 g/L |
Normal Blood Sodium Levels
| Serum sodium | mmol/L (mEq/L) | mg/dL |
|---|---|---|
| Normal range (adults) | 135 – 145 | 310 – 333 |
| Low sodium (hyponatremia) | below 135 | below 310 |
| Severe hyponatremia | below 125 | below 287 |
| High sodium (hypernatremia) | above 145 | above 333 |
The concentration of sodium in human blood is about 140 mmol/L, or roughly 3.2 g/L. Ranges vary slightly between laboratories. Low sodium can be caused by some medicines (such as diuretics), heart, liver or kidney disease, or drinking a very large amount of water; high sodium usually means dehydration. Use the range on your own report and discuss results with your doctor.
Sodium mg to mmol: Food, Diet and Salt
Nutrition labels list sodium in milligrams, while doctors and dietitians often use mmol. For a full chart with % Daily Value and salt, see the sodium mg to mmol converter. To convert sodium mg to mmol, divide by 23 (22.99). To convert sodium mmol to mg, multiply by 23.
| Sodium (mg) | Sodium (mmol) | Equivalent salt (g) |
|---|---|---|
| 23 mg | 1.0 mmol | 0.1 g |
| 100 mg | 4.3 mmol | 0.3 g |
| 200 mg | 8.7 mmol | 0.5 g |
| 230 mg | 10.0 mmol | 0.6 g |
| 400 mg | 17.4 mmol | 1.0 g |
| 500 mg | 21.7 mmol | 1.3 g |
| 1,000 mg | 43.5 mmol | 2.5 g |
| 1,500 mg | 65.2 mmol | 3.8 g |
| 2,000 mg | 87.0 mmol | 5.1 g |
| 2,300 mg | 100.0 mmol | 5.8 g |
| 3,000 mg | 130.5 mmol | 7.6 g |
| 4,000 mg | 174.0 mmol | 10.2 g |
| 5,000 mg | 217.5 mmol | 12.7 g |
| Sodium (mmol) | Sodium (mg) | Equivalent salt (g) |
|---|---|---|
| 1 mmol | 23 mg | 0.1 g |
| 5 mmol | 115 mg | 0.3 g |
| 10 mmol | 230 mg | 0.6 g |
| 20 mmol | 460 mg | 1.2 g |
| 50 mmol | 1,150 mg | 2.9 g |
| 87 mmol | 2,000 mg | 5.1 g |
| 100 mmol | 2,299 mg | 5.8 g |
| 150 mmol | 3,449 mg | 8.8 g |
| 200 mmol | 4,598 mg | 11.7 g |
The World Health Organization recommends less than 2,000 mg of sodium a day (about 87 mmol, or 5 g of salt). The widely used US limit of 2,300 mg equals 100 mmol of sodium, or about 5.8 g of salt. Note that 1 g of salt (sodium chloride) contains only about 393 mg (17.1 mmol) of sodium.
How to Convert Sodium mmol/L to mg/dL
- Take the serum sodium value in mmol/L, for example 138 mmol/L.
- Multiply by 22.99 to get mg/L: 138 × 22.99 = 3,173 mg/L.
- Divide by 10 to get mg/dL: 317.3 mg/dL. (Or simply multiply mmol/L by 2.299.)
To go back from mg/dL to mmol/L, divide by 2.299, or use the sodium mg/dL to mmol/L converter.
Corrected Sodium for High Blood Sugar
Very high glucose pulls water into the blood and lowers the measured sodium. A common correction (Katz) adds 1.6 mmol/L of sodium for every 100 mg/dL of glucose above 100 mg/dL, which is about 0.29 mmol/L per 1 mmol/L of glucose above 5.6 mmol/L. Some clinicians use 2.4 instead of 1.6. Convert your glucose with the glucose mmol/L to mg/dL calculator.
Frequently Asked Questions
How do I convert sodium from mmol/L to mg/dL?
Multiply mmol/L by 2.299. For example, 140 mmol/L × 2.299 = 321.9 mg/dL.
Is sodium mmol/L the same as mEq/L?
Yes. Sodium carries a single positive charge, so 1 mmol/L = 1 mEq/L. A sodium of 140 mmol/L is 140 mEq/L.
How many mg is 1 mmol of sodium?
1 mmol of sodium = 22.99 mg, usually rounded to 23 mg.
How do I convert sodium mg to mmol?
Divide milligrams by 23. For example, 2,300 mg ÷ 23 = 100 mmol of sodium.
What is the sodium concentration in human blood in g/L or mmol/L?
Normal blood sodium is 135–145 mmol/L, which is about 3.1–3.3 g/L.
What is 140 mmol/L sodium in mg/dL?
140 mmol/L = 321.9 mg/dL, a normal serum sodium level.
Why is sodium rarely reported in mg/dL?
Because sodium is an electrolyte, labs worldwide, including in the US, report it in mmol/L or mEq/L. mg/dL is mainly used in research or when comparing with other mass-based units.
Related: potassium mmol/L to mg/dL and all electrolyte and mineral conversions.