PPM To mg/L Of CaCO3 or Ca2+ Calculator (Water Hardness)

In the US, we usually express water hardness in terms of PPM (Parts Per Million). In many cases, however, we would like to express water hardness in mg/L of CaCO3 (calcium carbonate) or mg/L of Ca2+ (calcium ions). That’s we have prepared 2 key online tools for converting PPM to mg/L, namely:

  1. PPM to mg/L Calculator. You just insert PPMs, and the calculator automatically converts PPM to mg/l of CaCO3 as well as mg/l of Ca2+ (you get both results).
  2. PPM to mg/L Charts. In the 1st chart, you will see 0-1,000 PPMs converted to mg/L of CaCO3. In the 2nd chart, you will see 0-1,000 PPMs converted to mg/L of Ca2+. We have denoted soft water (0-60 ppm) with this green color, moderately hard water (61-120 ppm) with this light blue color, hard water (121-180 ppm) with this blue color, and very hard water (181+ ppm) with this dark blue color.

This conversion is pretty simple. Here are both formulas for this PPM to mg/l (milligrams per liter) conversion:

Water Hardness (mg/L Of CaCO3) = 1 × PPM

Water Hardness (mg/L Of Ca2+) = 0.40044 × PPM

Basically, 1 PPM is equal to 1 mg/L of CaCO3, and 1 PPM is equal to 0.40044 mg/L Ca2+.

Quick Example: Let’s say we want to convert 100 PPM to mg/L of CaCO3 and Ca2+. This is quite simple. From the equations above (or using the calculator below), we can see that:

  • 100 PPM is equal to 100 mg/L of CaCO3.
  • 100 PPM is equal to 40.04 mg/L of Ca2+.

For an even easier calculation, here is the calculator (with an example below), followed by both 1st PPM to mg/L CaCO3 conversion chart and 2nd PPM to mg/L Ca2+ conversion chart:

PPM To mg/L Calculator

 

Here is how this online PPM to mg/L calculator works:

Let’s say you have 140 PPM water hardness. How much is that in mg/L of CaCO3 and mg/L of Ca2+? Simply slide the PPM slider in the calculator to ‘140‘, and you get both of these results:

140 PPM is equal to 140 mg/L of CaCO3, and 140 PPM is equal to 56.06 mg/L of Ca2+ ions.

If you need to convert in reverse – mg/L to PPM – you can use our mg/L to PPM calculator here.

You can find both of these results (as well as many others between 0 and 1,000 PPM) in the charts below. Note that 140 PPM, for example, is considered hard water and is colored in this blue color for hard water in these 2 charts:

PPM To mg/L Of CaCO3 Chart (1st Chart)

PPM (Parts Per Million): mg/L Of CaCO3 (Calcium Carbonate):
0 PPM 0 mg/L Of CaCO3
1 PPM 1 mg/L Of CaCO3
5 PPM 5 mg/L Of CaCO3
10 PPM 10 mg/L Of CaCO3
15 PPM 15 mg/L Of CaCO3
20 PPM 20 mg/L Of CaCO3
25 PPM 25 mg/L Of CaCO3
30 PPM 30 mg/L Of CaCO3
35 PPM 35 mg/L Of CaCO3
40 PPM 40 mg/L Of CaCO3
45 PPM 45 mg/L Of CaCO3
50 PPM 50 mg/L Of CaCO3
60 PPM 60 mg/L Of CaCO3
70 PPM 70 mg/L Of CaCO3
80 PPM 80 mg/L Of CaCO3
90 PPM 90 mg/L Of CaCO3
100 PPM 100 mg/L Of CaCO3
110 PPM 110 mg/L Of CaCO3
120 PPM 120 mg/L Of CaCO3
130 PPM 130 mg/L Of CaCO3
140 PPM 140 mg/L Of CaCO3
150 PPM 150 mg/L Of CaCO3
160 PPM 160 mg/L Of CaCO3
170 PPM 170 mg/L Of CaCO3
180 PPM 180 mg/L Of CaCO3
190 PPM 190 mg/L Of CaCO3
200 PPM 200 mg/L Of CaCO3
250 PPM 250 mg/L Of CaCO3
300 PPM 300 mg/L Of CaCO3
350 PPM 350 mg/L Of CaCO3
400 PPM 400 mg/L Of CaCO3
450 PPM 450 mg/L Of CaCO3
500 PPM 500 mg/L Of CaCO3
550 PPM 550 mg/L Of CaCO3
600 PPM 600 mg/L Of CaCO3
650 PPM 650 mg/L Of CaCO3
700 PPM 700 mg/L Of CaCO3
750 PPM 750 mg/L Of CaCO3
800 PPM 800 mg/L Of CaCO3
850 PPM 850 mg/L Of CaCO3
900 PPM 900 mg/L Of CaCO3
950 PPM 950 mg/L Of CaCO3
1000 PPM 1000 mg/L Of CaCO3

As you can see, converting PPM to mg/L of CaCO3 is dead simple. Since 1 PPM = 1 mg/L CaCO3, you can see that PPMs and mg/L of CaCO3 (milligrams per liter) are practically the same unit. Hence, we see that:

  • Soft water contains anywhere from 0 to 60 mg/L of CaCO3.
  • Moderately hard water contains anywhere from 61 to 120 mg/L of CaCO3.
  • Hard water contains anywhere from 121 to 180 mg/L of CaCO3.
  • Very hard water contains more than 181 mg/L of CaCO3.

The PPM conversion to mg/L of Ca2 is a bit more interesting. Here is the whole conversion chart:

PPM To mg/L Of Ca2+ Ions Chart (2nd Chart)

PPM (Parts Per Million): mg/L Of Ca2+ (Calcium Ions):
0 PPM 0 mg/L Of Ca2+
1 PPM 0.40 mg/L Of Ca2+
5 PPM 2.00 mg/L Of Ca2+
10 PPM 4.00 mg/L Of Ca2+
15 PPM 6.01 mg/L Of Ca2+
20 PPM 8.01 mg/L Of Ca2+
25 PPM 10.01 mg/L Of Ca2+
30 PPM 12.01 mg/L Of Ca2+
35 PPM 14.02 mg/L Of Ca2+
40 PPM 16.02 mg/L Of Ca2+
45 PPM 18.02 mg/L Of Ca2+
50 PPM 20.02 mg/L Of Ca2+
60 PPM 24.03 mg/L Of Ca2+
70 PPM 28.03 mg/L Of Ca2+
80 PPM 32.04 mg/L Of Ca2+
90 PPM 36.04 mg/L Of Ca2+
100 PPM 40.04 mg/L Of Ca2+
110 PPM 44.05 mg/L Of Ca2+
120 PPM 48.05 mg/L Of Ca2+
130 PPM 52.06 mg/L Of Ca2+
140 PPM 56.06 mg/L Of Ca2+
150 PPM 60.07 mg/L Of Ca2+
160 PPM 64.07 mg/L Of Ca2+
170 PPM 68.07 mg/L Of Ca2+
180 PPM 72.08 mg/L Of Ca2+
190 PPM 76.08 mg/L Of Ca2+
200 PPM 80.09 mg/L Of Ca2+
250 PPM 100.11 mg/L Of Ca2+
300 PPM 120.13 mg/L Of Ca2+
350 PPM 140.15 mg/L Of Ca2+
400 PPM 160.18 mg/L Of Ca2+
450 PPM 180.20 mg/L Of Ca2+
500 PPM 200.22 mg/L Of Ca2+
550 PPM 220.25 mg/L Of Ca2+
600 PPM 240.27 mg/L Of Ca2+
650 PPM 260.29 mg/L Of Ca2+
700 PPM 280.32 mg/L Of Ca2+
750 PPM 300.34 mg/L Of Ca2+
800 PPM 320.36 mg/L Of Ca2+
850 PPM 340.39 mg/L Of Ca2+
900 PPM 360.41 mg/L Of Ca2+
950 PPM 380.43 mg/L Of Ca2+
1000 PPM 400.45 mg/L Of Ca2+

We see that converting PPM to mg/L of calcium ions is a bit more difficult. We have to multiply PPMs by a factor of 0.40044 to get the mg/L of Ca2+. Here is the water hardness categorization in terms of mg/L of calcium ions:

  • Soft water contains anywhere from 0 to 24.03 mg/L of Ca2+.
  • Moderately hard water contains anywhere from 24.04 to 48.05 mg/L of Ca2+.
  • Hard water contains anywhere from 48.06 to 72.08 mg/L of Ca2+.
  • Very hard water contains more than 72.09 mg/L of Ca2+.

Hopefully, this gives you all you need to convert water hardness PPM units to mg/L of CaCO3 and calcium ions. If you need a bit of extra  insight about this water hardness unit conversion, you can use the comment section below, give us some numbers, and we will help you out.

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