Fever Temperature Chart
Use these charts to read a thermometer in Celsius or Fahrenheit and see whether it shows a fever. Thresholds differ by measurement method and by age, especially for young babies.
Fever thresholds by measurement method
| Method | Fever at or above (°C) | Fever at or above (°F) |
|---|---|---|
| Rectal | 38.0 | 100.4 |
| Ear (tympanic) | 38.0 | 100.4 |
| Forehead (temporal) | 38.0 | 100.4 |
| Oral (mouth) | 37.8 | 100.0 |
| Armpit (axillary) | 37.2 | 99.0 |
Adult temperature chart (oral)
| °C | °F | Category |
|---|---|---|
| 35.5 | 95.9 | Low |
| 36.1 | 97 | Normal |
| 36.6 | 97.9 | Normal |
| 37 | 98.6 | Normal |
| 37.5 | 99.5 | Normal / slightly raised |
| 37.8 | 100 | Low-grade fever |
| 38.3 | 100.9 | Fever |
| 38.9 | 102 | Fever |
| 39.4 | 102.9 | High fever |
| 40 | 104 | High fever |
| 41.1 | 106 | Very high fever |
Baby & child temperature chart (rectal)
| °C | °F | Under 3 months | 3 months and older |
|---|---|---|---|
| 36.5 | 97.7 | Normal | Normal |
| 37.5 | 99.5 | Normal | Normal |
| 38 | 100.4 | Call a doctor | Fever |
| 38.5 | 101.3 | Call a doctor | Fever |
| 38.9 | 102 | Call a doctor | Call a doctor if 3–36 months |
| 39.5 | 103.1 | Call a doctor | High fever — call a doctor |
| 40 | 104 | Call a doctor | High fever — call a doctor |
Notes
When to call a doctor
- Babies under 3 months: any rectal temperature of 38 °C (100.4 °F) or higher.
- Babies and toddlers 3–36 months: 38.9 °C (102 °F) or higher, or a fever lasting more than a day.
- Children and adults: 39.4 °C (103 °F) or higher, a fever lasting more than three days, or a fever with symptoms such as a stiff neck, confusion, difficulty breathing or a rash.
This chart is general information compiled from widely published guidance and is not medical advice. Always follow the advice of your own healthcare provider.
Frequently asked questions
What temperature is a fever for a baby?
A rectal temperature of 38 °C (100.4 °F) or higher. For babies under 3 months, contact a doctor right away at this temperature.
Is 99 °F a fever?
Not for an oral, rectal or ear reading. An armpit reading of 99 °F (37.2 °C) is at the usual armpit fever threshold.
What is a high fever in adults?
39.4 °C (103 °F) or higher is generally considered a high fever in adults and a reason to contact a doctor.