IoT Power Budget Calculator

Battery life from sensor duty cycle and transmission frequency.

Battery capacity (mAh)

Active current (mA)

Sleep current (uA)

Wake time per cycle (s)

Cycle period (s)

TX current (mA)

TX duration (ms)

Self-discharge (%/yr)

Tab to move between fields

Average current (mA)

0.61

Battery life (days)133.6

Battery life (months)4.4

Battery life (years)0.37

Duty cycle (%)3.42

Daily energy (mWh)47.9

How to Use This Calculator

Enter your battery capacity in mAh (e.g., AA = 2500 mAh, CR2032 = 225 mAh).
Set active current (mA) during sensor reading and sleep current (uA) in deep-sleep mode.
Enter wake time per cycle in seconds and the full cycle period in seconds.
Input TX current (mA) and TX duration (ms) for your radio technology (BLE, LoRa, WiFi).
Review Battery life in days, months, and years alongside the Duty cycle percentage.
Reduce cycle period or TX duration if battery life is too short for your deployment target.

What each input means

Battery capacity (mAh): Total battery capacity in milliamp-hours. E.g. CR2032 = 225 mAh, AA = 2500 mAh.
Active current (mA): Current draw during sensor reading / processing in milliamps.
Sleep current (uA): Deep-sleep current draw in microamps. Modern MCUs: 1-10 uA.
Wake time per cycle (s): Seconds the device is active (sensing + processing) each cycle.
Cycle period (s): Total seconds per wake/sleep cycle. 60 = once per minute.
TX current (mA): Radio transmit current in mA. BLE ~15 mA, LoRa ~120 mA, WiFi ~250 mA.
TX duration (ms): Duration of each radio transmission in milliseconds.
Self-discharge (%/yr): Annual battery self-discharge rate. Li primary ~1-3%, alkaline ~5-10%.

Average current (mA): Weighted average current consumption across the full duty cycle.
Battery life (days): Estimated battery life in days.
Battery life (months): Estimated battery life in months.
Battery life (years): Estimated battery life in years.
Duty cycle (%): Percentage of time the device is active (wake + TX).
Daily energy (mWh): Daily energy consumption at 3.3V nominal voltage.

Identify Input Parameters
4 parameters
Battery capacity (mAh) = 2000, Active current (mA) = 15, Sleep current (uA) = 5, Wake time per cycle (s) = 2 = 8 input(s) provided
Calculate Average current
Average current = (activeEnergy + txEnergy + sleepEnergy) / cyclePeriod
0.605 = 0.605
Calculate Battery life
Battery life = batteryLifeHours / 24
133.6 = 133.6
Calculate Battery life
Battery life = batteryLifeDays / 30.44
4.4 = 4.4