Convert Parts per million to Parts per trillion
1 part per million is 1,000,000 ppt. One part per million is exactly 1000000 parts per trillion.
One part per million is 1000000 parts per trillion. To convert parts per million to parts per trillion, multiply by 1000000; to go the other way, divide by 1000000 or multiply by 1.0000 × 10^-6. The factor is exact rather than rounded: it follows from NIST SP 811 §7.10.3. One in a million.
Factor checked against the defining standard · How we check
- Parts per million × 1000000
1 * 10000001,000,000 ppt
1 part per million in every concentration unit
| Unit | Value | Exact factor |
|---|---|---|
| per cent | 0.0001 % | × 0.0001 |
| per mille | 0.001 ‰ | × 0.001 |
| parts per million (as entered) | 1 ppm | — |
| parts per billion | 1,000 ppb | × 1,000 |
| parts per trillion | 1,000,000 ppt | × 1,000,000 |
Factors are entered by hand from NIST SP 811 §7.10.3 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert parts per million to parts per trillion? The converter and the working
- 1.Take the measurement in parts per million.
- 2.Multiply by 1000000 — that is how many parts per trillion fit in one part per million.
- 3.To go back the other way, divide by 1000000, or multiply by 1.0000 × 10^-6.
Worked example: 25 parts per million to parts per trillion
- Formula
- ppm × 1000000 = ppt
- Arithmetic
- 25 × 1000000 = 25,000,000 ppt
- Answer
- 25 ppm = 25,000,000 ppt
The factor is exact, so this figure is exact too — only the display is rounded.
Parts per million to parts per trillion conversion table
| Parts per million | Parts per trillion |
|---|---|
| 1 ppm | 1,000,000 ppt |
| 2 ppm | 2,000,000 ppt |
| 3 ppm | 3,000,000 ppt |
| 4 ppm | 4,000,000 ppt |
| 5 ppm | 5,000,000 ppt |
| 6 ppm | 6,000,000 ppt |
| 7 ppm | 7,000,000 ppt |
| 8 ppm | 8,000,000 ppt |
| 9 ppm | 9,000,000 ppt |
| 10 ppm | 10,000,000 ppt |
| 12 ppm | 12,000,000 ppt |
| 15 ppm | 15,000,000 ppt |
| 20 ppm | 20,000,000 ppt |
| 25 ppm | 25,000,000 ppt |
| 50 ppm | 50,000,000 ppt |
| 100 ppm | 100,000,000 ppt |
| 200 ppm | 200,000,000 ppt |
| 300 ppm | 300,000,000 ppt |
| 500 ppm | 500,000,000 ppt |
| 1000 ppm | 1,000,000,000 ppt |
| 2000 ppm | 2,000,000,000 ppt |
| 5000 ppm | 5,000,000,000 ppt |
| 10000 ppm | 10,000,000,000 ppt |
What is a part per million?
One in a million. The working unit of drinking-water limits, CO₂ in air and dissolved solids — 1 ppm is 1 mg per liter of water, since a liter weighs a kilogram.
What is a part per trillion?
One in a million million. PFAS limits are set here — the EPA’s 2024 drinking-water rule is 4 ppt, which is four drops in a thousand Olympic pools.
How many parts per trillion are in a part per million?
One part per million is 1000000 parts per trillion, exactly. Going the other way, one part per trillion is 1.0000 × 10^-6 parts per million. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every concentration unit here
The whole group — 5 units with their symbols and the size of each one in part per millions — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a part per million.
Source: NIST SP 811 §7.10.3 — why ppm, ppb and ppt should be avoided and what they mean
Cite this page
- APA
- Rule Calculator. (2026). Convert Parts per million to parts per trillion. Rule Calculator. https://rulecalculators.com/convert/ppm-to-ppt
- MLA
- "Convert Parts per million to parts per trillion." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/ppm-to-ppt.
- Chicago
- Rule Calculator. "Convert Parts per million to parts per trillion." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/ppm-to-ppt.
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Questions people actually ask
- How many parts per trillion are in a part per million?
- 1000000. One in a million million. PFAS limits are set here — the EPA’s 2024 drinking-water rule is 4 ppt, which is four drops in a thousand Olympic pools.
- How do I convert parts per trillion back to parts per million?
- Divide by 1000000, or multiply by 1.0000 × 10^-6 — they are the same operation.
Other concentration conversions
Parts per trillion to parts per million — the same conversion the other way.