Battery Life Calculator — Real-World Battery Estimation

This calculator adjusts the manufacturer CIPA rating to a real-world estimate using two derating factors — your shooting style and a camera-type factor:

Real-World Shots

Real shots = rated shots × style multiplier × camera-type factor

The style multiplier ranges from 1.0 (conservative — rarely reviewing, no video) down to 0.4 (very heavy — continuous AF, video, cold weather). The camera-type factor is 1.0 for a DSLR and an adjustable real-world derate (default 0.7) for mirrorless, reflecting the EVF/LCD and always-on sensor. Because manufacturer CIPA ratings are already measured on that specific body, treat this factor as a general “real-world vs CIPA” allowance, not an extra mirrorless penalty — set it to 1.0 if your camera matches or beats its CIPA figure.

Shooting Duration

Hours = real shots ÷ shots per hour

Batteries Needed

Batteries = ceiling(shoot duration ÷ hours per battery)

CIPA DC-002 measures shots per charge under fixed conditions (50% flash, an image every 30 s, power-off after every 10 shots). Real-world endurance commonly runs 50–80% of the CIPA figure for heavy LCD, video or cold use, but efficient EVF shooting with a fresh battery can match or exceed it — adjust the factors to suit how you shoot.