Interpreting Temperature Ratings

Sleeping bags are often rated with both “comfort” and “limit” temperatures. The comfort rating generally describes the lowest temperature at which an average sleeper will remain comfortable without feeling cold. The limit rating indicates the threshold for staying alive in harsh conditions. Manufacturers use lab tests based on standardized protocols, but personal factors—such as metabolism, shelter type, and clothing—affect real-world performance. It helps to convert between Fahrenheit and Celsius so you can compare gear from different brands.

The Conversion Formula

To convert Fahrenheit to Celsius, subtract 32 and multiply by 5/9. To convert Celsius to Fahrenheit, multiply by 9/5 and add 32. In MathML, that's $C=\frac{5}{9}\times F-32$ and $F=\frac{9}{5}\times C+32$. This calculator performs the conversion automatically and shows the equivalent value on the other scale.

Sample Ratings Table

The following table demonstrates typical ranges for three-season sleeping bags. These values are just examples—always check the manufacturer's specific rating.

Comfort (°C)	Comfort (°F)	Limit (°C)	Limit (°F)
5	41	-1	30
0	32	-7	19
-5	23	-12	10

Choosing the Right Bag

When selecting a sleeping bag, consider the lowest nighttime temperature you expect on your trips. Layering clothing inside the bag can extend its range by a few degrees. A well-insulated sleeping pad also prevents heat loss to the ground. Keep your bag clean and dry for maximum performance. Over time, down and synthetic fills compress, reducing warmth—track the comfort rating so you know when it's time to replace or professionally clean the bag.

The equation $T=\mathrm{T\_r}+L$ can help account for layering, where $\mathrm{T\_r}$ is the bag rating and $L$ is the warmth added by clothing in degrees. Adjust this factor based on personal experience and the type of layers you plan to wear.

Final Reminders

Use this converter whenever you shop for new camping gear or compare global brands. Copy the result for quick reference while you plan your adventures. Staying warm at night makes every outdoor trip more enjoyable.