TDS To EC Calculator: Convert TDS (PPM) To EC (µS/cm) (+3 Charts)

We use a TDS meter a bunch to measure PPMs (Parts Per Million) in water solutions. From that, we convert TDS to EC (expressed in µS/cm or microsiemens per centimeter). We have created 2 tools (TDS to EC calculator + 3 conversion charts) to make this conversion easy, and we are sharing it with you all.

Now, to really help everybody who wants to convert TDS measurement to EC (Electric Conductivity), we need to account for 3 different PPM scales across the world (TDS meters – Total Dissolved Solids meters – measure PPMs a bit differently due to KCl, NaCl, etc. calibrations).

Here’s what you need to know before using TDS to EC calculator and the accompanying 3 charts:

  • TDS meters sold in the US use a 500 PPM scale (NaCl calibration). That means that 1 TDS unit (PPM) is equal to 2 EC units (µS/cm).
  • TDS meters sold in Europe and internationally have a 640 PPM scale. That means that 1 TDS is equal to 1.56 EC (µS/cm).
  • Australians have their own thing going; their TDS meters use a 700 PPM scale. Thus, in Australia, 1 TDS is equal to 1.43 EC (µS/cm).

From this, we see that where you bought a TDS meter (US, Europe, Australia) matters a lot. We will explain the math further on, but let’s start with the TDS to EC calculator, and we follow up with all 3 charts (we converted 1-1000 TDS units to EC, and summarized all the results in 3 different charts, corresponding to 3 TDS meter types).

Here is the calculator we use, you can freely use it (it’s easy):

 

Alright, let’s solve 1 example to demonstrate how the calculator works.

In the photo above, you can see that we used a US-made TDS meter and measured 165 PPM (red circle). To convert this 165 PPM TDS measurement to EC, we just slide the TDS slider to ‘165’, pick ‘United States Of America’, and you get this result (screenshot):

convert tds to ec with an online calculator

This is how we can easily convert measured with our US-made TDS meter to EC. Now, we know that 165 TDS is equal to 330 EC (µS/cm).

We usually just use the conversion chart nowadays, to be honest. Before we check all 3 conversion charts, let’s quickly go over the math of how this conversion works:

How Do You Convert TDS To EC? (Formula, Calculation)

With a US-based TDS meter, we know the following:

US: 1 TDS (PPM) = 2 EC (µS/cm)

If you are from Europe, Australia, or the rest of the world, you will need to use the following 2 conversion relationships (due to different TDS PPM scales used):

Europe, International: 1 TDS (PPM) = 1.56 EC (µS/cm)

Australia: 1 TDS (PPM) = 1.43 EC (µS/cm)

For simple calculations, we can write all these 3 relationships as TDS to EC formulas like this:

US Formula: EC = TDS × 0.5

Europe, International Formula: EC = TDS × 0.64

Australian Formula: EC = TDS × 0.7

Using these, it’s quite easy to make this conversion. To get EC, we need to multiply TDS by 0.5 (for US TDS meters), by 0.64 (for European, international TDS meters, and Australians – who were brilliant enough to start using their own 700 PPM scale – have to convert TDS by 0.7 to get the resulting EC.

Let’s try one example just for fun:

How many EC is 300 TDS?

Simple. Let’s insert 300 TDS in the 3 equations above like this:

US: EC (300 TDS) = 300 TDS × 0.5 = 600 EC (µS/cm)

Europe, International: EC (300 TDS) = 300 TDS × 0.64 = 468.75 EC (µS/cm)

Australian: EC (300 TDS) = 300 TDS × 0.7 = 428.57 EC (µS/cm)

We can clearly see that 300 TDS (PPM) is equal to 600 EC (µS/cm) if we use a US TDS meter, 468.75 EC if we use a European one, and 428.57 EC if we use an Australian TDS meter.

We clearly see that we get different results (again, because of these different PPM scales). For the quickest TDS to EC conversion, we use the following 3 conversion charts (1st chart is for US, 2nd chart is for Europe/international, and the 3rd chart is for the Aussies):

1. TDS To EC Conversion Chart (US TDS PPM Scale)

In the US, we use TDS meters with a 500 PPM scale. Here is the conversion chart:

TDS US Meter (PPM or Parts Per Million): EC (µS/cm or Microsiemens Per Centimeter):
1 TDS Measurement (PPM) 2 EC (µS/cm)
5 TDS Measurement (PPM) 10 EC (µS/cm)
10 TDS Measurement (PPM) 20 EC (µS/cm)
15 TDS Measurement (PPM) 30 EC (µS/cm)
20 TDS Measurement (PPM) 40 EC (µS/cm)
25 TDS Measurement (PPM) 50 EC (µS/cm)
30 TDS Measurement (PPM) 60 EC (µS/cm)
35 TDS Measurement (PPM) 70 EC (µS/cm)
40 TDS Measurement (PPM) 80 EC (µS/cm)
45 TDS Measurement (PPM) 90 EC (µS/cm)
50 TDS Measurement (PPM) 100 EC (µS/cm)
60 TDS Measurement (PPM) 120 EC (µS/cm)
70 TDS Measurement (PPM) 140 EC (µS/cm)
80 TDS Measurement (PPM) 160 EC (µS/cm)
90 TDS Measurement (PPM) 180 EC (µS/cm)
100 TDS Measurement (PPM) 200 EC (µS/cm)
110 TDS Measurement (PPM) 220 EC (µS/cm)
120 TDS Measurement (PPM) 240 EC (µS/cm)
130 TDS Measurement (PPM) 260 EC (µS/cm)
140 TDS Measurement (PPM) 280 EC (µS/cm)
150 TDS Measurement (PPM) 300 EC (µS/cm)
160 TDS Measurement (PPM) 320 EC (µS/cm)
170 TDS Measurement (PPM) 340 EC (µS/cm)
180 TDS Measurement (PPM) 360 EC (µS/cm)
190 TDS Measurement (PPM) 380 EC (µS/cm)
200 TDS Measurement (PPM) 400 EC (µS/cm)
250 TDS Measurement (PPM) 500 EC (µS/cm)
300 TDS Measurement (PPM) 600 EC (µS/cm)
350 TDS Measurement (PPM) 700 EC (µS/cm)
400 TDS Measurement (PPM) 800 EC (µS/cm)
450 TDS Measurement (PPM) 900 EC (µS/cm)
500 TDS Measurement (PPM) 1000 EC (µS/cm)
550 TDS Measurement (PPM) 1100 EC (µS/cm)
600 TDS Measurement (PPM) 1200 EC (µS/cm)
650 TDS Measurement (PPM) 1300 EC (µS/cm)
700 TDS Measurement (PPM) 1400 EC (µS/cm)
750 TDS Measurement (PPM) 1500 EC (µS/cm)
800 TDS Measurement (PPM) 1600 EC (µS/cm)
850 TDS Measurement (PPM) 1700 EC (µS/cm)
900 TDS Measurement (PPM) 1800 EC (µS/cm)
950 TDS Measurement (PPM) 1900 EC (µS/cm)
1000 TDS Measurement (PPM) 2000 EC (µS/cm)

2. TDS To EC Conversion Chart (European, International TDS PPM Scale)

In Europe and internationally, we use TDS meters with a 640 PPM scale. Here is the conversion chart:

TDS European, International Meter (PPM): EC (µS/cm or Microsiemens Per Centimeter):
1 TDS Measurement (PPM) 1.56 EC (µS/cm)
5 TDS Measurement (PPM) 7.81 EC (µS/cm)
10 TDS Measurement (PPM) 15.63 EC (µS/cm)
15 TDS Measurement (PPM) 23.44 EC (µS/cm)
20 TDS Measurement (PPM) 31.25 EC (µS/cm)
25 TDS Measurement (PPM) 39.06 EC (µS/cm)
30 TDS Measurement (PPM) 46.88 EC (µS/cm)
35 TDS Measurement (PPM) 54.69 EC (µS/cm)
40 TDS Measurement (PPM) 62.50 EC (µS/cm)
45 TDS Measurement (PPM) 70.31 EC (µS/cm)
50 TDS Measurement (PPM) 78.13 EC (µS/cm)
60 TDS Measurement (PPM) 93.75 EC (µS/cm)
70 TDS Measurement (PPM) 109.38 EC (µS/cm)
80 TDS Measurement (PPM) 125.00 EC (µS/cm)
90 TDS Measurement (PPM) 140.63 EC (µS/cm)
100 TDS Measurement (PPM) 156.25 EC (µS/cm)
110 TDS Measurement (PPM) 171.88 EC (µS/cm)
120 TDS Measurement (PPM) 187.50 EC (µS/cm)
130 TDS Measurement (PPM) 203.13 EC (µS/cm)
140 TDS Measurement (PPM) 218.75 EC (µS/cm)
150 TDS Measurement (PPM) 234.38 EC (µS/cm)
160 TDS Measurement (PPM) 250.00 EC (µS/cm)
170 TDS Measurement (PPM) 265.63 EC (µS/cm)
180 TDS Measurement (PPM) 281.25 EC (µS/cm)
190 TDS Measurement (PPM) 296.88 EC (µS/cm)
200 TDS Measurement (PPM) 312.50 EC (µS/cm)
250 TDS Measurement (PPM) 390.63 EC (µS/cm)
300 TDS Measurement (PPM) 468.75 EC (µS/cm)
350 TDS Measurement (PPM) 546.88 EC (µS/cm)
400 TDS Measurement (PPM) 625.00 EC (µS/cm)
450 TDS Measurement (PPM) 703.13 EC (µS/cm)
500 TDS Measurement (PPM) 781.25 EC (µS/cm)
550 TDS Measurement (PPM) 859.38 EC (µS/cm)
600 TDS Measurement (PPM) 937.50 EC (µS/cm)
650 TDS Measurement (PPM) 1015.63 EC (µS/cm)
700 TDS Measurement (PPM) 1093.75 EC (µS/cm)
750 TDS Measurement (PPM) 1171.88 EC (µS/cm)
800 TDS Measurement (PPM) 1250.00 EC (µS/cm)
850 TDS Measurement (PPM) 1328.13 EC (µS/cm)
900 TDS Measurement (PPM) 1406.25 EC (µS/cm)
950 TDS Measurement (PPM) 1484.38 EC (µS/cm)
1000 TDS Measurement (PPM) 1562.50 EC (µS/cm)

3. TDS To EC Conversion Chart (Australian TDS PPM Scale)

In Australia, we use TDS meters with a special 700 PPM scale. Here is the conversion chart:

TDS Australian Meter (PPM): EC (µS/cm or Microsiemens Per Centimeter):
1 TDS Measurement (PPM) 1.43 EC (µS/cm)
5 TDS Measurement (PPM) 7.14 EC (µS/cm)
10 TDS Measurement (PPM) 14.29 EC (µS/cm)
15 TDS Measurement (PPM) 21.43 EC (µS/cm)
20 TDS Measurement (PPM) 28.57 EC (µS/cm)
25 TDS Measurement (PPM) 35.71 EC (µS/cm)
30 TDS Measurement (PPM) 42.86 EC (µS/cm)
35 TDS Measurement (PPM) 50.00 EC (µS/cm)
40 TDS Measurement (PPM) 57.14 EC (µS/cm)
45 TDS Measurement (PPM) 64.29 EC (µS/cm)
50 TDS Measurement (PPM) 71.43 EC (µS/cm)
60 TDS Measurement (PPM) 85.71 EC (µS/cm)
70 TDS Measurement (PPM) 100.00 EC (µS/cm)
80 TDS Measurement (PPM) 114.29 EC (µS/cm)
90 TDS Measurement (PPM) 128.57 EC (µS/cm)
100 TDS Measurement (PPM) 142.86 EC (µS/cm)
110 TDS Measurement (PPM) 157.14 EC (µS/cm)
120 TDS Measurement (PPM) 171.43 EC (µS/cm)
130 TDS Measurement (PPM) 185.71 EC (µS/cm)
140 TDS Measurement (PPM) 200.00 EC (µS/cm)
150 TDS Measurement (PPM) 214.29 EC (µS/cm)
160 TDS Measurement (PPM) 228.57 EC (µS/cm)
170 TDS Measurement (PPM) 242.86 EC (µS/cm)
180 TDS Measurement (PPM) 257.14 EC (µS/cm)
190 TDS Measurement (PPM) 271.43 EC (µS/cm)
200 TDS Measurement (PPM) 285.71 EC (µS/cm)
250 TDS Measurement (PPM) 357.14 EC (µS/cm)
300 TDS Measurement (PPM) 428.57 EC (µS/cm)
350 TDS Measurement (PPM) 500.00 EC (µS/cm)
400 TDS Measurement (PPM) 571.43 EC (µS/cm)
450 TDS Measurement (PPM) 642.86 EC (µS/cm)
500 TDS Measurement (PPM) 714.29 EC (µS/cm)
550 TDS Measurement (PPM) 785.71 EC (µS/cm)
600 TDS Measurement (PPM) 857.14 EC (µS/cm)
650 TDS Measurement (PPM) 928.57 EC (µS/cm)
700 TDS Measurement (PPM) 1000.00 EC (µS/cm)
750 TDS Measurement (PPM) 1071.43 EC (µS/cm)
800 TDS Measurement (PPM) 1142.86 EC (µS/cm)
850 TDS Measurement (PPM) 1214.29 EC (µS/cm)
900 TDS Measurement (PPM) 1285.71 EC (µS/cm)
950 TDS Measurement (PPM) 1357.14 EC (µS/cm)
1000 TDS Measurement (PPM) 1428.57 EC (µS/cm)

The calculator and the charts help us a lot. We hope that you find them useful as well. You are now fully equipped to convert TDS to EC (Total Dissolved Solids to Electrical Conductivity) yourself. If you need a bit of help from our side, you are welcome to use the comment section below, give us a few numbers, and we can do some math together.

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