Convert Seconds to Milliseconds
1 second (s) equals 1000 milliseconds (ms).
1 s = 1000 ms
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk second to millisecond converter to paste a column from Excel.
How to Convert Second to Millisecond
- 1 s = 1000 ms
- 1 ms = 0.001 s
- Example: convert 15 s to ms: 15 s = 15 × 1000 ms = 15000 ms
Formula
ms = s × 1000
Derivation from SI units:
- SI base unit: 9 192 631 770 periods of the caesium-133 hyperfine transition
- 1 ms = 10⁻³ s
Both units are defined exactly, so the factor is exact. Second definition: second; Millisecond definition: millisecond.
Worked examples
- One cycle of 50 Hz mains power lasts 0.02 s, or 20 ms.
0.02 s × 1000 = 20 ms - A 1.5 s timeout is entered as 1500 ms in most programming languages.
1.5 s × 1000 = 1500 ms
Second to Millisecond conversion table
| Seconds (s) | Milliseconds (ms) |
|---|---|
| 0.001 s | 1 ms |
| 0.01 s | 10 ms |
| 0.1 s | 100 ms |
| 0.5 s | 500 ms |
| 1 s | 1000 ms |
| 2 s | 2000 ms |
| 5 s | 5000 ms |
| 10 s | 10000 ms |
| 15 s | 15000 ms |
| 20 s | 20000 ms |
| 30 s | 30000 ms |
| 45 s | 45000 ms |
| 60 s | 60000 ms |
| 90 s | 90000 ms |
| 100 s | 100000 ms |
| 120 s | 120000 ms |
| 180 s | 180000 ms |
| 300 s | 300000 ms |
| 600 s | 600000 ms |
| 900 s | 900000 ms |
| 1800 s | 1800000 ms |
| 3600 s | 3600000 ms |
| 7200 s | 7200000 ms |
| 86400 s | 86400000 ms |
Where it's used
Timeouts, delays and sampling intervals in code and PLC timers are usually entered in milliseconds, so values worked out in seconds are multiplied by 1000.
Second to other time units
| Conversion | 1 s equals |
|---|---|
| second to millisecond | 1000 ms |
| second to minute | 0.01666666667 min |
| second to hour | 0.0002777777778 h |
| second to day | 0.00001157407407 d |
Frequently asked questions
How many milliseconds are in a second?
Exactly 1000.
How many milliseconds are in 1 second?
1 s = 1000 ms.
How do I convert seconds to milliseconds?
Multiply the value in s by 1000. For example, 15 s × 1000 = 15000 ms.
Is the s to ms conversion exact?
Yes. Both units are defined exactly, and 1 s is exactly 1000 ms.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Section 2.3.1, base unit definitions.
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Seconds to Milliseconds. Retrieved October 17, 2026, from https://scientificconverters.com/time/seconds-to-milliseconds/
IEEE
Scientific Converters, "Convert Seconds to Milliseconds," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/time/seconds-to-milliseconds/