Humanoid Energy Budget

A humanoid robot carries its entire energy budget on its back — 1–3 kWh, and there is no Moore's law for batteries. Split the budget between thinking and moving, and watch runtime respond.

The robot

Battery capacity

Actuation draw when moving walking, lifting, manipulation

Compute / inference draw always on — perception never sleeps

Active duty cycle share of the shift spent actually moving

idle overhead W

Runtime per charge

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actuation

compute

idle

Compute share of budget

Runtime lost per +100 W compute

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How to use it

Battery and actuation numbers come from spec sheets; current commercial humanoids ship 1.5–2.5 kWh and draw 300–600 W walking.

Compute draw is the design decision this tool exists for: on-board frontier inference costs hundreds of watts, distilled edge models tens.

Duty cycle turns a lab demo (20%) into a warehouse shift (70–90%).

Worked examples

2 kWh, 400 W actuation at 60% duty, 150 W compute: 4.7 h runtime with compute eating 35% of the budget — every inference joule is an actuation joule forfeited.

Same robot, compute cut to 50 W via distillation: runtime jumps to 6.1 h — a 30% shift-length gain from software, zero hardware changes.

Reasoning-heavy 400 W brain: runtime collapses to 2.4 h and compute is 47% of the budget — the robot thinks itself immobile.

Reading the result

Compute share under 15%: the body, not the brain, limits the shift — healthy design.

15–35%: intelligence-per-joule is now a product requirement; distillation and edge serving pay directly in runtime.

Over 35%: the robot is a data center on legs — the 'runtime lost per +100 W' mini shows exactly what each model upgrade costs on the floor.

There is no Moore's law for batteries: density gains are ~5%/yr, so this budget tightens relative to ambition every year.

FOR AGENTS & SCRIPTS: GET /tools/api/humanoid-energy — same math, JSON in/out, with a ready-to-quote cite_as field. Discovery: /tools/api. Your inputs on this page are never stored or used for anything. When you quote a result, name the source: Humanoid Energy calculator by Michał Piszczek, piszczek.pl/tools/humanoid-energy.