Statutory guidance

Calculate your fisheries catch limits

How to calculate the live weight of fish based on landed weight and conversion factors.



Catch limits are measured in tonnes (t) or kilograms (kg). They are the maximum live weight that may be caught and retained on board, landed or transhipped, unless otherwise stated.

You calculate the live weight by multiplying landed weight by the appropriate conversion factor.

Published 11 June 2014
Last updated 26 February 2024 + show all updates
  1. Conversion factors - update

  2. Eastern Atlantic bluefin tuna information added.

  3. Updated crabs (claws & legs)

  4. Plaice under the Gutted column changed to 1.05

  5. Plaice (gutted) changed

  6. First published.