# Forums

## Rated Mileage vs how to calculate actual day to day mileage

On a full charge my car hits 269 rated miles, which i think is based on 300 Wh/mi, correct? If so can someone help calculate my actual useful miles based on my avg of 331 Wh/mi. I drive 62 miles round trip (up and down hills, some stop lights but mostly 72mph on cruise control) a day to work and have watched my avg Wh/mi fluctuate right around this 331. So if my full rated miles based on 300 Wh/mi is 269 miles. How far can I actually drive my car based on 331 Wh/mi (not counting the overnight drag / vampire loss)?

thanks

Blueshift | 26 septembre 2013

On a full charge my car hits 269 rated miles, which i think is based on 300 Wh/mi, correct?

Assuming that the above is true, I believe this is the answer to your question:

LET

c = your useable battery capacity

THEN

(c Wh) / (300 Wh / mi ) = 269 miles

SOLVING FOR c:

c = (300 Wh/mi)*(268 mi) = 80,700 Wh = 80.7 kWh

NOW, assume you use that capacity c at 331 Wh/mi.

(80,700 Wh) / (331 Wh/mi) = 243.8 miles

Blueshift | 26 septembre 2013

So 244 miles, which is close to the default range setting on my new supercharger map: http://www.teslawiki.net/supercharger/

BD | 26 septembre 2013