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Motor Power Budget Checker

V5RC limits motor power in watts, not motor count. Check your drivetrain against the 55W subsystem cap and your robot against the 88W total.

Inputs

Drivetrain (Subsystem 1)

Everything else

Intake, lift, arm, and any other subsystem.

Results

Legal?

—

Drivetrain power

—

Rule R11a caps this at 55W.

Total robot power

—

Rule R10a caps this at 88W.

Drivetrain headroom

—W

Total headroom

—W

Motors used

—

Drivetrain watts, against the rule—

Rule R11a caps the drivetrain on its own.

Total watts, against the rule—

Rule R10a caps every motor on the robot added together.

When you would use this

  1. We got told at inspection that our robot was illegal.

    Enter your motors exactly as they are fitted. The two verdicts show which cap you broke, and the headroom figures show how much you have to remove. Most failures are the drivetrain cap rather than the total.

  2. We want a sixth drive motor.

    Add it here first. If the drivetrain headroom goes negative you cannot have it, and the tool tells you how many 5.5W motors you could fit in the same watts instead, which is often the real answer.

  3. We are deciding between a six motor drive and a four motor drive with a stronger lift.

    Run both layouts. The total headroom left over is what the rest of the robot gets to spend, and seeing that number move is a better argument in a design review than an opinion about what feels fast.

  4. Judges asked why we chose this motor layout.

    This is the evidence for that answer: what the rules allow, what you fitted, and what you deliberately left spare. The notebook export at the bottom turns it into an entry with the reasoning prompts already in place.

  5. We keep browning out and wonder if we have too many motors.

    Legal and sensible are different questions. This page answers the first one. Take the same layout to the current and battery budget to answer the second, because a legal robot can still ask for more than the battery gives.

How this is calculated

The rule most teams remember is "eight motors". That has not been the rule for some time. V5RC now budgets motor power, and there are two separate caps you must satisfy at once.

drivetrain power = (11W drive motors × 11) + (5.5W drive motors × 5.5) total power = drivetrain power + everything else legal when drivetrain ≤ 55W AND total ≤ 88W

Both motor types count at their full rated value. A 5.5W motor is not free. It costs half a motor's worth of budget for meaningfully less than half the performance, which is why it is usually a poor choice on a drivetrain and a sensible one on a light mechanism.

What the drivetrain cap actually costs you

The 55W subsystem cap is the binding constraint on most drivebase designs. In practice it means:

  • Four 11W motors. 44W, the common choice, leaves headroom.
  • Five 11W motors. 55W, exactly at the cap. Nothing spare.
  • Six 11W motors. 66W, over. Not legal, whatever the total.

Spending more on the drive directly reduces what is left for scoring mechanisms out of the 88W total. That trade is the real design decision, and it is worth making on purpose rather than discovering it at inspection.

One more restriction

Rule R11b prohibits power take-off from the drivetrain: a motor counted in Subsystem 1 may not also drive something that is not part of the drivetrain. You cannot dodge the cap with a clever differential or a clutch.

Sources & assumptions

Power caps are rules R10a (88W total) and R11a (55W on Subsystem 1) from the Override 2026-27 game manual, with R11b prohibiting power take-off. Motor ratings of 11W and 5.5W are VEX published figures.

This checker covers motor power only. It does not check the many other rules an inspector will apply, and passing here does not mean a robot passes inspection.

Save this run, and compare

Keeps what is on screen so you can change something and see both sides of the change. Saved in this browser only, never uploaded.

Save this as evidence

Collects what you entered, what came out, how it was worked out, and anything the tool flagged, with a timestamp and a version so someone else can reproduce it.

This is evidence, not a notebook entry. It deliberately does not write your problem statement, your reasoning, or your conclusion, because under RECF rules an Engineering Notebook has to be the students' own work and no tool may generate or organise its content. Take the numbers, decide what matters, and write it yourself.