mg/mL To Molarity Calculator: Convert mg/mL To mol/L (Formula + 4 Charts)

Concentration of water solution is usually give in mg/mL (milligrams per milliliter) or mol/L (moles per liter or molarity (M)). You often have mg/mL concentration, and you want to know the molarity (concentration in mol/L). Here, we will show you exactly how to convert mg/mL to molarity with these 3 key resources:

  1. mg/L To Molarity Calculator. Here, you insert mg/mL concentration and molar mass (Example: NaCl has 58.44 g/mol molar mass), and you will get molarity immediately.
  2. How To Calculate Molarity From mg/ml Concentration? We explain the math behind this conversion (mg/ml to molarity formula), and solve 2-3 examples to illustrate how to convert mg/mL to mol/L for any chemical substance.
  3. mg/L To Molarity Charts (4 of them). We do a lot of work with water hardness; that’s why we deal with CaCO3, CaO, Ca2+, and Mg2+ concentrations. We converted 0.1 – 1000 mg/mL to molarity (mol/l) for these 4 substances, and summarized all the results in 4 big charts (also added a bit of color to the charts so that they look nice).

Note: If you need any help, you can use the comment section below, give us the chemical substance and some numbers, and we can convert mg/mL to molarity for you.

Here is the mg/mL to mol/L calculator you can freely use, followed by the math and the 4 conversion charts:

 

Let’s solve one example just to illustrate how this calculator works:

What is the molarity of 5 mg/mL HCl (hydrochloric acid)? We know HCl has a molar mass of 36.46 g/mol. We just input the ‘5’ mg/mL concentration in the 1st input field, and we input ‘36.46’ in the 2nd molar mass field. Here is the result we get (screenshot):

convert mg ml to M or molarity in terms of moles per liter

We can see that 5 mg/mL HCL has a 0.1371 mol/L molarity (0.1371 M).

Alright, let’s look under the hood of this calculator and explain the math behind it:

How To Calculate Molarity From mg/mL Concentration? (Formula)

For all of these conversion, we use this mg/L to mol/L formula:

Molarity (mol/L) = mg/ml / Molar Mass

So, if we want to convert milligrams per milliliter (mg/mL) concentration to moles per liter (molarity), we need to divide mg/ml concentration by molar mass.

Example: Let’s say we are working with 10 mg/mL KCl. KCl (potassium chloride) has a molar mass of 74.55 g/mol. We just insert these two data points into the equation above like this:

Molarity (10 mg/mL KCL) = 10 mg/ml / 74.55 g/mol = 0.1341 mol/L

Simple, right?

We can see that the only thing that determines the mg/mL to molarity conversion is molar mass. Namely, the bigger the molar mass a molecule has, the lower the molarity we will get (for the same mg/mL concentration). Here are 1 mg/mL concentrations converted to molarity just to illustrate this point:

  • 1 mg/mL NaCl = 0.0171 mol/L (or 17.1 mmol/L)
  • 1 mg/mL H2SO4 = 0.0102 mol/L (or 10.2 mmol/L)
  • 1 mg/mL KCl = 0.0134 mol/L (or 13.4 mmol/L)
  • 1 mg/mL NaOH = 0.0250 mol/L (or 25 mmol/L)
  • 1 mg/mL CaCO3 = 0.0100 mol/L (or 10 mmol/L)
  • 1 mg/mL Mg(OH)2 = 0.0171 mol/L (or 17.1 mmol/L)
1 mg to ml for different chemical substances in test tubes
1 mg/mL of different chemical substances have different molarities (M) because their molar mass differs.

We see that 1 mg/mL NaOH has the highest molarity (0.0250 mol/L) here because it has the lowest molar mass (40 g/mol). On the other end of the spectra, 1 mg/mL CaCO3 has the lowest molarity here (0.0100 mol/L) because it has the highest molar mass (100.08 g/mol).

These are just 1 mg/mL = mol/L conversion. We can converted all the concentrations ranging from 0.1 mg/mL to 1000 mg/L to molarity (mol/L) for 4 key chemicals (CaCO3, CaO, Ca2+, Mg2+) that we use when dealing with water hardness assessments. Here are the promised 4 conversion charts:

mg/mL CaCO3 To Molarity Chart (1st Chart)

CaCO3 or calcium carbonate has a molar mass of 100.08 g/mol. Here are the conversions to molarity:

mg/mL Of CaCO3 (Calcium Carbonate): Molarity (mol/L CaCO3):
0.1 mg/mL CaCO3 0.0010 mol/L CaCO3
0.5 mg/mL CaCO3 0.0050 mol/L CaCO3
1 mg/mL CaCO3 0.0100 mol/L CaCO3
2 mg/mL CaCO3 0.0200 mol/L CaCO3
3 mg/mL CaCO3 0.0300 mol/L CaCO3
4 mg/mL CaCO3 0.0400 mol/L CaCO3
5 mg/mL CaCO3 0.0500 mol/L CaCO3
6 mg/mL CaCO3 0.0600 mol/L CaCO3
7 mg/mL CaCO3 0.0699 mol/L CaCO3
8 mg/mL CaCO3 0.0799 mol/L CaCO3
9 mg/mL CaCO3 0.0899 mol/L CaCO3
10 mg/mL CaCO3 0.0999 mol/L CaCO3
15 mg/mL CaCO3 0.1499 mol/L CaCO3
20 mg/mL CaCO3 0.1998 mol/L CaCO3
25 mg/mL CaCO3 0.2498 mol/L CaCO3
30 mg/mL CaCO3 0.2998 mol/L CaCO3
35 mg/mL CaCO3 0.3497 mol/L CaCO3
40 mg/mL CaCO3 0.3997 mol/L CaCO3
45 mg/mL CaCO3 0.4496 mol/L CaCO3
50 mg/mL CaCO3 0.4996 mol/L CaCO3
60 mg/mL CaCO3 0.5995 mol/L CaCO3
70 mg/mL CaCO3 0.6994 mol/L CaCO3
80 mg/mL CaCO3 0.7994 mol/L CaCO3
90 mg/mL CaCO3 0.8993 mol/L CaCO3
100 mg/mL CaCO3 0.9992 mol/L CaCO3
200 mg/mL CaCO3 1.9984 mol/L CaCO3
300 mg/mL CaCO3 2.9976 mol/L CaCO3
400 mg/mL CaCO3 3.9968 mol/L CaCO3
500 mg/mL CaCO3 4.9960 mol/L CaCO3
600 mg/mL CaCO3 5.9952 mol/L CaCO3
700 mg/mL CaCO3 6.9944 mol/L CaCO3
800 mg/mL CaCO3 7.9936 mol/L CaCO3
900 mg/mL CaCO3 8.9928 mol/L CaCO3
1,000 mg/mL CaCO3 (1 g/mL) 9.9920 mol/L CaCO3

mg/mL CaO To Molarity Chart (2nd Chart)

CaO or calcium oxide has a molar mass of 56.08 g/mol. Here are the conversions to molarity:

mg/mL Of CaO (Calcium Oxide): Molarity (mol/L CaO):
0.1 mg/mL CaO 0.0018 mol/L CaO
0.5 mg/mL CaO 0.0089 mol/L CaO
1 mg/mL CaO 0.0178 mol/L CaO
2 mg/mL CaO 0.0357 mol/L CaO
3 mg/mL CaO 0.0535 mol/L CaO
4 mg/mL CaO 0.0713 mol/L CaO
5 mg/mL CaO 0.0892 mol/L CaO
6 mg/mL CaO 0.1070 mol/L CaO
7 mg/mL CaO 0.1248 mol/L CaO
8 mg/mL CaO 0.1427 mol/L CaO
9 mg/mL CaO 0.1605 mol/L CaO
10 mg/mL CaO 0.1783 mol/L CaO
15 mg/mL CaO 0.2675 mol/L CaO
20 mg/mL CaO 0.3566 mol/L CaO
25 mg/mL CaO 0.4458 mol/L CaO
30 mg/mL CaO 0.5350 mol/L CaO
35 mg/mL CaO 0.6241 mol/L CaO
40 mg/mL CaO 0.7133 mol/L CaO
45 mg/mL CaO 0.8024 mol/L CaO
50 mg/mL CaO 0.8916 mol/L CaO
60 mg/mL CaO 1.0699 mol/L CaO
70 mg/mL CaO 1.2482 mol/L CaO
80 mg/mL CaO 1.4265 mol/L CaO
90 mg/mL CaO 1.6049 mol/L CaO
100 mg/mL CaO 1.7832 mol/L CaO
200 mg/mL CaO 3.5663 mol/L CaO
300 mg/mL CaO 5.3495 mol/L CaO
400 mg/mL CaO 7.1327 mol/L CaO
500 mg/mL CaO 8.9158 mol/L CaO
600 mg/mL CaO 10.6990 mol/L CaO
700 mg/mL CaO 12.4822 mol/L CaO
800 mg/mL CaO 14.2653 mol/L CaO
900 mg/mL CaO 16.0485 mol/L CaO
1,000 mg/mL CaO (1 g/mL) 17.8317 mol/L CaO

mg/mL Ca2+ To Molarity Chart (3rd Chart)

Ca2+ or calcium ions have a molar mass of 40.08 g/mol. Here are the conversions to molarity:

mg/mL Of Ca2+ (Calcium Ions): Molarity (mol/L Ca2+):
0.1 mg/mL Ca2+ 0.0025 mol/L Ca2+
0.5 mg/mL Ca2+ 0.0125 mol/L Ca2+
1 mg/mL Ca2+ 0.0250 mol/L Ca2+
2 mg/mL Ca2+ 0.0499 mol/L Ca2+
3 mg/mL Ca2+ 0.0749 mol/L Ca2+
4 mg/mL Ca2+ 0.0998 mol/L Ca2+
5 mg/mL Ca2+ 0.1248 mol/L Ca2+
6 mg/mL Ca2+ 0.1497 mol/L Ca2+
7 mg/mL Ca2+ 0.1747 mol/L Ca2+
8 mg/mL Ca2+ 0.1996 mol/L Ca2+
9 mg/mL Ca2+ 0.2246 mol/L Ca2+
10 mg/mL Ca2+ 0.2495 mol/L Ca2+
15 mg/mL Ca2+ 0.3743 mol/L Ca2+
20 mg/mL Ca2+ 0.4990 mol/L Ca2+
25 mg/mL Ca2+ 0.6238 mol/L Ca2+
30 mg/mL Ca2+ 0.7485 mol/L Ca2+
35 mg/mL Ca2+ 0.8733 mol/L Ca2+
40 mg/mL Ca2+ 0.9980 mol/L Ca2+
45 mg/mL Ca2+ 1.1228 mol/L Ca2+
50 mg/mL Ca2+ 1.2475 mol/L Ca2+
60 mg/mL Ca2+ 1.4970 mol/L Ca2+
70 mg/mL Ca2+ 1.7465 mol/L Ca2+
80 mg/mL Ca2+ 1.9960 mol/L Ca2+
90 mg/mL Ca2+ 2.2455 mol/L Ca2+
100 mg/mL Ca2+ 2.4950 mol/L Ca2+
200 mg/mL Ca2+ 4.9900 mol/L Ca2+
300 mg/mL Ca2+ 7.4850 mol/L Ca2+
400 mg/mL Ca2+ 9.9800 mol/L Ca2+
500 mg/mL Ca2+ 12.4750 mol/L Ca2+
600 mg/mL Ca2+ 14.9701 mol/L Ca2+
700 mg/mL Ca2+ 17.4651 mol/L Ca2+
800 mg/mL Ca2+ 19.9601 mol/L Ca2+
900 mg/mL Ca2+ 22.4551 mol/L Ca2+
1,000 mg/mL Ca2+ (1 g/mL) 24.9501 mol/L Ca2+

mg/mL Mg2+ To Molarity Chart (4th Chart)

Mg2+ or magnesium ions have a molar mass of 24.31 g/mol. Here are the conversions to molarity:

mg/mL Of Mg2+ (Magnesium Ions): Molarity (mol/L Mg2+):
0.1 mg/mL Mg2+ 0.0041 mol/L Mg2+
0.5 mg/mL Mg2+ 0.0206 mol/L Mg2+
1 mg/mL Mg2+ 0.0411 mol/L Mg2+
2 mg/mL Mg2+ 0.0823 mol/L Mg2+
3 mg/mL Mg2+ 0.1234 mol/L Mg2+
4 mg/mL Mg2+ 0.1645 mol/L Mg2+
5 mg/mL Mg2+ 0.2057 mol/L Mg2+
6 mg/mL Mg2+ 0.2468 mol/L Mg2+
7 mg/mL Mg2+ 0.2879 mol/L Mg2+
8 mg/mL Mg2+ 0.3291 mol/L Mg2+
9 mg/mL Mg2+ 0.3702 mol/L Mg2+
10 mg/mL Mg2+ 0.4114 mol/L Mg2+
15 mg/mL Mg2+ 0.6170 mol/L Mg2+
20 mg/mL Mg2+ 0.8227 mol/L Mg2+
25 mg/mL Mg2+ 1.0284 mol/L Mg2+
30 mg/mL Mg2+ 1.2341 mol/L Mg2+
35 mg/mL Mg2+ 1.4397 mol/L Mg2+
40 mg/mL Mg2+ 1.6454 mol/L Mg2+
45 mg/mL Mg2+ 1.8511 mol/L Mg2+
50 mg/mL Mg2+ 2.0568 mol/L Mg2+
60 mg/mL Mg2+ 2.4681 mol/L Mg2+
70 mg/mL Mg2+ 2.8795 mol/L Mg2+
80 mg/mL Mg2+ 3.2908 mol/L Mg2+
90 mg/mL Mg2+ 3.7022 mol/L Mg2+
100 mg/mL Mg2+ 4.1135 mol/L Mg2+
200 mg/mL Mg2+ 8.2271 mol/L Mg2+
300 mg/mL Mg2+ 12.3406 mol/L Mg2+
400 mg/mL Mg2+ 16.4541 mol/L Mg2+
500 mg/mL Mg2+ 20.5677 mol/L Mg2+
600 mg/mL Mg2+ 24.6812 mol/L Mg2+
700 mg/mL Mg2+ 28.7947 mol/L Mg2+
800 mg/mL Mg2+ 32.9083 mol/L Mg2+
900 mg/mL Mg2+ 37.0218 mol/L Mg2+
1,000 mg/mL Mg2+ (1 g/mL) 41.1353 mol/L Mg2+

Hopefully, now you understand how to convert mg/mL to mol/L (molarity). You can use the calculator, do the math yourself using the mg/L to molarity formula, or consult one of these 4 charts. If you need any help from our side, you can give us some numbers and chemicals in the comments below, and we can do a bit of math for you.

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