Convert Per cent to Parts per trillion
1 per cent is 10,000,000,000 ppt. One per cent is exactly 10000000000 parts per trillion.
One per cent is 10000000000 parts per trillion. To convert per cent to parts per trillion, multiply by 10000000000; to go the other way, divide by 10000000000 or multiply by 1.0000 × 10^-10. The factor is exact rather than rounded: it follows from NIST SP 811 §7.10.3. Parts per hundred.
Factor checked against the defining standard · How we check
- Per cent × 10000000000
1 * 1000000000010,000,000,000 ppt
1 per cent in every concentration unit
| Unit | Value | Exact factor |
|---|---|---|
| per cent (as entered) | 1 % | — |
| per mille | 10 ‰ | × 10 |
| parts per million | 10,000 ppm | × 10,000 |
| parts per billion | 10,000,000 ppb | × 10,000,000 |
| parts per trillion | 10,000,000,000 ppt | × 10,000,000,000 |
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 per cent to parts per trillion? The converter and the working
- 1.Take the measurement in per cent.
- 2.Multiply by 10000000000 — that is how many parts per trillion fit in one per cent.
- 3.To go back the other way, divide by 10000000000, or multiply by 1.0000 × 10^-10.
Worked example: 25 per cent to parts per trillion
- Formula
- % × 10000000000 = ppt
- Arithmetic
- 25 × 10000000000 = 250,000,000,000 ppt
- Answer
- 25 % = 250,000,000,000 ppt
The factor is exact, so this figure is exact too — only the display is rounded.
Per cent to parts per trillion conversion table
| Per cent | Parts per trillion |
|---|---|
| 1 % | 10,000,000,000 ppt |
| 2 % | 20,000,000,000 ppt |
| 3 % | 30,000,000,000 ppt |
| 4 % | 40,000,000,000 ppt |
| 5 % | 50,000,000,000 ppt |
| 6 % | 60,000,000,000 ppt |
| 7 % | 70,000,000,000 ppt |
| 8 % | 80,000,000,000 ppt |
| 9 % | 90,000,000,000 ppt |
| 10 % | 100,000,000,000 ppt |
| 12 % | 120,000,000,000 ppt |
| 15 % | 150,000,000,000 ppt |
| 20 % | 200,000,000,000 ppt |
| 25 % | 250,000,000,000 ppt |
| 50 % | 500,000,000,000 ppt |
| 100 % | 1,000,000,000,000 ppt |
| 200 % | 2,000,000,000,000 ppt |
| 300 % | 3,000,000,000,000 ppt |
| 500 % | 5,000,000,000,000 ppt |
| 1000 % | 10,000,000,000,000 ppt |
| 2000 % | 20,000,000,000,000 ppt |
| 5000 % | 50,000,000,000,000 ppt |
| 10000 % | 100,000,000,000,000 ppt |
What is a per cent?
Parts per hundred. One per cent is 10,000 ppm, which is the conversion people reach for when a water report and a lab result are in different units.
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 per cent?
One per cent is 10000000000 parts per trillion, exactly. Going the other way, one part per trillion is 1.0000 × 10^-10 per cent. 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 per cent.
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 Per cent to parts per trillion. Rule Calculator. https://rulecalculators.com/convert/percent-to-ppt
- MLA
- "Convert Per cent to parts per trillion." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/percent-to-ppt.
- Chicago
- Rule Calculator. "Convert Per cent to parts per trillion." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/percent-to-ppt.
The date is when the figures on this page were last checked against their source, not the day you opened it. Add your own access date if your style needs one.
Questions people actually ask
- How many parts per trillion are in a per cent?
- 10000000000. 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 per cent?
- Divide by 10000000000, or multiply by 1.0000 × 10^-10 — they are the same operation.
Other concentration conversions
Parts per trillion to per cent — the same conversion the other way.