Check luggage weight against an airline allowance

Compare one packed bag with one airline allowance and price a simple per-kilogram overage.

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ToolLuggage Weight Calculator
Input
Output
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How it works

Bag kilograms minus allowed kilograms determine either spare capacity or excess, never both. Positive excess is multiplied by the entered per-kilogram fee, which can remain zero for a weight-only check.

Formula
excess fee = max(0, bag kg − allowance kg) × fee per kg
  • Allowance and bag weight come from the booking and scale rather than defaults.
  • Fees are not fetched because carriers price routes, fares, airports, and purchase channels differently.

Worked example

25kg bag, 23kg allowance
A bag over the limit, with a fee per kilogram over
Input
											Bag weight kg: 25
Allowance kg: 23
Excess fee per kg: 12
Output
												Bag weight kg: 25
Allowance kg: 23
Within allowance: no
Spare kg: 0
Excess kg: 2
Excess fee: 24

When to use this

Checked bags are weighed against booking limits, travellers repack before check-in, and airlines with a simple per-kilogram rate can be costed in the relevant currency.

Edge cases

  • Two passenger allowances may not be poolable into one heavier bag; only one bag against one entered allowance is checked.
  • Piece-based fees, maximum bag caps, and oversize dimensions cannot be represented by a per-kilogram charge.
  • Exact equality is marked within allowance without adding a margin for differences between home and airport scales.