Conversion method
Temperature differences use scale factors only: 1 K = 1 °C interval = 1.8 °F interval. No absolute-temperature offset applies; cooling intervals may be negative.
Δ°F = x × 1.7999999999999998
10 ΔK = 18 Δ°F.
| ΔK | Δ°F |
|---|---|
| 1 | 1.8 |
| 5 | 9 |
| 10 | 18 |
| 25 | 45 |
| 50 | 90 |
| 100 | 180 |
Unit definitions and sources
Temperature differences use scale factors only: 1 K = 1 °C interval = 1.8 °F interval. No absolute-temperature offset applies; cooling intervals may be negative.
| Unit and system | Use | Definition | Relationship |
|---|---|---|---|
| Kelvin interval (ΔK); si | Common units | Kelvin interval: base (delta-k) = value × 1. Common use: Temperature Interval. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Fahrenheit interval (Δ°F); si | Common units | Fahrenheit interval: base (delta-k) = value × 0.5555555555555556. Common use: Temperature Interval. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Celsius interval (Δ°C); si | Specialist units | Celsius interval: base (delta-k) = value × 1. Common use: Temperature Interval. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Rankine interval (Δ°R); si | Specialist units | Rankine interval: base (delta-k) = value × 0.5555555555555556. Common use: Temperature Interval. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Kelvin (K); other | Specialist units | kelvin = 1.0 delta-k, derived from the component SI/customary definitions. Common use: Temperature Interval. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Degree Celsius (K); other | Specialist units | degree Celsius = 1.0 delta-k, derived from the component SI/customary definitions. Common use: Temperature Interval. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Degree centigrade (K); other | Specialist units | degree centigrade = 1.0 delta-k, derived from the component SI/customary definitions. Common use: Temperature Interval. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
Sources: NIST: SP 811 Appendix B.8: conversion factors; BIPM: SI prefixes
Precision of temperature interval conversions
All 7 temperature interval units convert through Kelvin interval (ΔK). 7 have an exact defined relationship to the base unit and 0 are conventional or measured values. Results and the tables on this page come from the same engine, so a table value can be checked against the converter directly.
Standard display shows up to six decimal places, switching to scientific notation for very large or small values. Calculation uses JavaScript binary floating point independently of display rounding, so extra digits are not a claim about measurement accuracy. Each unit lists its own source; a citation records where the definition comes from, not an independent review. See Conversion methodology for the review and correction process.