Convert temperature instantly between Celsius, Fahrenheit, and Kelvin. Type a value, pick units, and see all 3 conversions live - all processing stays in your browser.
Technical Specifications
Formulas and limits used for every calculation.
| Specification |
Details |
| Supported units |
Celsius (C), Fahrenheit (F), Kelvin (K) - 3 units |
| Base unit |
Celsius (C). All conversions go through Celsius. |
| Formulas |
C to F: F = C x 9/5 + 32 | F to C: C = (F - 32) x 5/9 | C to K: K = C + 273.15 | K to C: C = K - 273.15 |
| Absolute zero |
0 K = -273.15 C = -459.67 F. Values below 0 K are blocked with an error. |
| Precision |
Double precision (IEEE 754). Display up to 9 decimal places, trailing zeros trimmed; exponential for |n| >= 1e12 or |n| < 1e-6 |
| Input handling |
Commas ignored, decimal points accepted, negatives allowed. Empty or invalid shows helper message. Update is live on input. |
| Matrix |
Every keystroke also recomputes the All Units grid: input amount shown in all 3 units relative to the From unit. |
| Processing location |
100% client-side JavaScript in your browser memory; nothing is uploaded |
| Export |
Copy result to clipboard or download a plain-text report with inputs, result, and all-units table |
| Usage limit |
None - run unlimited conversions for free, no signup required |
Understanding Temperature Units
Temperature measures heat energy but scales use different zero points. Celsius sets 0 at water's freezing point, Fahrenheit sets 32 at the same point, and Kelvin sets 0 at absolute zero where molecular motion stops. That offset means conversions need addition, not just multiplication.
Celsius and Fahrenheit
Celsius is used worldwide for weather and science, divided into 100 steps between freezing and boiling water. Fahrenheit is used mainly in the United States. Convert with F = C x 9/5 + 32. For example 0 C is 32 F, 20 C is 68 F, and 100 C is 212 F. Reverse with C = (F - 32) x 5/9.
Kelvin and absolute zero
Kelvin is the SI base unit for thermodynamics, starting at absolute zero (0 K = -273.15 C). Convert with K = C + 273.15 and C = K - 273.15. Because Kelvin has no negative values, the tool blocks any input that would produce below 0 K and shows an error instead.
When to use which unit
Use Celsius for everyday weather and cooking outside the US, Fahrenheit for US weather and body temperature, and Kelvin for scientific calculations like gas laws. If a project spans scales, convert through Celsius with the formulas above - for example 68 F to Kelvin is (68-32) x 5/9 + 273.15 = 293.15 K.
Honest limitations
Display rounding hides trailing noise but near absolute zero tiny floating errors are trimmed to 9 decimals. Values beyond 1e12 degrees switch to exponential form. The tool does not handle Rankine or Delisle - for those, use the specialized Length Converter or Weight Converter patterns.
Privacy and Client-Side Security
Privacy Guarantee: All conversions occur locally inside your browser. Your numbers and selected units are never transmitted, stored, or recorded on remote servers.
Many online converters send your inputs to a server for lookup, which is unnecessary for fixed-formula math. TinyToolzz keeps everything in-page: formulas and formatting run with plain JavaScript number operations.
Because nothing is uploaded, there is no waiting, no account, and no copy of your figures retained anywhere. Your values exist only in the tab's memory and are discarded when you close the page or click Clear.