Maximum Baggage Calculator (Weight & CG Limited)
How much can the baggage bay really take today? The lesser of the structural placard, the gross-weight gap and the aft-CG headroom — computed, not guessed.
Three ceilings, one answer: the placard (structure), the gross gap (lift) and the CG headroom (stability) — and which one binds changes with every loading. Aft-CG-limited days are the ones pilots fail to notice.
Formula
⚠️ For planning and education only. Weight & balance must be computed from YOUR aircraft's actual empty weight, arm and current equipment list, and verified against the POH/AFM envelope before flight.
How much can the baggage bay really take today? The lesser of the structural placard, the gross-weight gap and the aft-CG headroom — computed, not guessed.
About Maximum Baggage Calculator (Weight & CG Limited)
“It says 120 pounds on the placard” answers the wrong question. The bay's real capacity today is the smallest of three ceilings: the structural placard, the remaining gap to max gross, and — the one that ambushes people — the weight that drives the CG to its aft limit, computed from the weight-addition formula. This calculator evaluates all three, reports the binding constraint by name, and shows how a heavy cabin can shrink a 120-pound bay to forty.
How to use Maximum Baggage Calculator (Weight & CG Limited)
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula max W = min(placard, MTOW − W, W·(aft − CG)/(arm_bag − aft)); the CG term from the addition formula substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Maximum Baggage Calculator (Weight & CG Limited)?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula max W = min(placard, MTOW − W, W·(aft − CG)/(arm_bag − aft)); the CG term from the addition formula with sources cited on the page
- ✓Three ceilings, one answer: the placard (structure), the gross gap (lift) and the CG headroom (stability) — and which one binds changes with every loading. Aft-CG-limited days are the ones pilots fail to notice.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
How can the aft CG limit allow less than the placard?+
The placard protects the floor structure; the envelope protects controllability — independent constraints. With the cabin loaded aft (full rear seats, light fuel), the CG may sit barely an inch from the aft limit, and each baggage pound at a long arm spends that inch fast. The addition formula quantifies it: permitted weight shrinks as (aft − CG) shrinks.
What is the weight-addition formula this tool inverts?+
Adding weight W at arm a moves the CG to (W₀·CG₀ + W·a)/(W₀+W). Setting the result equal to the aft limit and solving for W gives the headroom: W = W₀(aft − CG₀)/(a − aft). It's the removal/addition sibling of the shift formula — and an FAA written-test staple in its own right.
Why does the binding constraint change day to day?+
Because the three ceilings move independently: gross-weight headroom shrinks with fuel and people; CG headroom shrinks specifically with aft-loaded cabins; the placard never moves. A solo pilot with full tanks is placard-limited; four adults with half tanks are gross-limited; light fuel with a full rear bench is CG-limited. Same airplane, three different answers.
Does it matter where in the bay the bags sit?+
In aircraft with one placarded station, the published arm is the required planning number. Multi-station bays (areas A/B, forward/aft holds) each have arms and placards — load the forward station first when CG headroom binds, and run this tool per station. Physically restraining bags matters too: a 40-lb case sliding aft in turbulence relocates its own arm.
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