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Weights and sinkers: converting ounces, grams and swan shot

Explainer · Last reviewed 2026-08-14

Two of the three systems British anglers use for weight convert exactly. The third — the traditional shot sizes — does not, and this record exists mainly to say so rather than to publish a table that would look authoritative and would not be.

ANGLERS EXPRESS WEIGHT IN THREE SYSTEMS AND ONLY TWO OF THEM ARE UNITS.

OUNCES AND GRAMS ARE EXACT. One international avoirdupois ounce is defined as exactly 28.349523125 grams. British and American beach and boat leads are marked in ounces; continental lure rods are rated in grams; and the conversion between them is a multiplication by a defined constant with no error in it. That conversion is available in the unit converter and it is trustworthy.

ONE PRACTICAL CAVEAT ON IT: leads are manufactured in convenient fractions of an ounce, so a converted figure will rarely land on a size that exists. A rod rated to 100 grams is rated to roughly three and a half ounces, and the leads on the shelf will be three, four and five.

THE TRADITIONAL SHOT SIZES ARE NOT A UNIT SYSTEM. The British sequence — SSG, SG, AAA, BB, and the numbered sizes running down from 1 to 8 and beyond — is a NAMED SEQUENCE inherited from shotgun pellet sizes. The names have conventional nominal weights and those nominal weights are not standardised: they differ between manufacturers, they have drifted over time, and the tolerance on a tin of shot is wider than the difference between adjacent sizes at the small end.

SO THIS RECORD DOES NOT PUBLISH A SHOT WEIGHT TABLE. A table would present a precision the underlying objects do not have, it would be indistinguishable on the page from one that does, and somebody would use it to calculate a float's shot capacity to two decimal places. What is publishable is the ORDERING — the sequence from largest to smallest — and the fact that the large sizes are named and the small ones numbered, with the numbers running DOWN as the shot gets smaller, which is the same counter-intuitive direction hook sizes run in above the pivot.

WHAT THIS MEANS PRACTICALLY, and it is more useful than a table.

FLOATS ARE RATED IN SHOT, NOT IN GRAMS, in the British tradition — a float takes '4 BB' or '3AAA' — and the rating is a statement about that float with that manufacturer's shot. Matching by weight across brands introduces error the whole system was never designed to carry.

SHOTTING IS DONE BY OBSERVATION RATHER THAN BY ARITHMETIC. The correct shotting is the one where the float sits with the intended amount of tip showing, in the water you are fishing, which you establish by looking. Calculating it and trusting the calculation is how people end up with an under-shotted float that a fish can feel.

AND NON-LEAD ALTERNATIVES CHANGE THE ARITHMETIC ENTIRELY. Tungsten is denser than lead and tin and steel are less dense, so a shot of the same NAME in a different material is a different weight and a different size. Where lead is restricted — and it is, in several jurisdictions and for several sizes — the substitution is not like for like, and any nominal figure inherited from lead does not carry across.

THE HONEST SUMMARY: convert ounces and grams freely, treat shot sizes as names rather than numbers, and set a float by looking at it.

Shot sizes are names rather than weights, and the substitutes are not equivalent

Converting ounces to grams is arithmetic. The weights an angler actually handles include a system that is not arithmetic at all, and it catches people out in two directions.

SPLIT SHOT ARE SIZED BY NAME, NOT BY MASS. The sequence runs through numbered and lettered sizes — the numbers descending as the shot gets larger, then a lettered series above them — and the naming is a convention rather than a measurement. An angler shotting a float works in these names, and the relationship between a name and a mass is something to look up rather than to calculate.

WHICH MATTERS BECAUSE FLOATS ARE RATED IN THEM. A float marked for a particular combination of shot is describing a total mass in a vocabulary of names, so getting the names wrong gets the shotting wrong, which is the commonest reason a float lies flat or sits too high.

AND THE SUBSTITUTES ARE NOT LIKE FOR LIKE. Lead is dense; tungsten is denser; tin and steel are considerably less dense. A shot of the same NAME in a different material is a different weight and a different size, so a float shotted with tin does not carry the same load as one shotted with lead, and a swap that looks equivalent changes the presentation.

THIS IS ALSO WHERE AN ANGLER MEETS A RULE DIRECTLY. Lead is toxic, its use in particular weight ranges in angling has been restricted in some jurisdictions, and the restricted range covers precisely the sizes a float rig is built from. That makes the material question a regulatory one as well as a technical one, and it is a question for the authority for the water rather than an assumption.

LEAD WEIGHT SIZING IN SEA FISHING IS SIMPLER AND STILL SPLIT. Ounces in Britain and grams almost everywhere else, with beach leads sold in both and rod ratings quoted in whichever the manufacturer prefers.

WHICH IS WHY THE CONVERSION TOOL CONVERTS MASSES AND SAYS NOTHING ABOUT SHOT SIZES. A conversion is exact; a shot-size table is a convention that varies, and publishing one as though it were a constant would be exactly the false precision the tool ledger exists to refuse.

Authoritative guidance

Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.

  • Freshwater Fishing — Macdonald & Jane's, 1975 (Specialist angling publication)Relied on for: Comprehensive angling practice including terminal arrangements, leaders, droppers and the knots each is made with.States this directlyCitation checked — the work exists and is described correctly
  • Coarse Fishing — A. & C. Black, 1912 (Specialist angling publication)Relied on for: Classical coarse angling practice: hooklength attachment, loops, shotting and the arrangements they carry.States this directlyCitation checked — the work exists and is described correctly
  • Sea Angler — Bauer Media (Specialist angling publication)Relied on for: Long-running published description of British sea angling practice, including trace construction, dropper loops and shock leaders.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
  • General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated descriptions of established terminal and connection convention, recorded as practitioner consensus rather than as scholarship.Background and mechanism onlyCitation checked — the work exists and is described correctly

Where to go next

Gear this affects

What these connections rest on (1)

Practitioner consensus — 1 connection

Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.

  • Sinkers and leads

    A mechanism edge from a record to the reasoning beneath it, resting on practice reported consistently across independent sources rather than on experiment.

    • Angling Times — Bauer Media (Specialist angling publication)Relied on for: Contemporary UK coarse, match and lure angling practice as reported by practitioners, including tackle convention.States this directlyCitation checked — the work exists and is described correctly
    • Sea Angler — Bauer Media (Specialist angling publication)Relied on for: Contemporary UK sea angling practice as reported by practitioners, including tackle, bait and lure convention.States this directlyCitation checked — the work exists and is described correctly

Related reading

What these connections rest on (2)

Practitioner consensus — 2 connections

Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.

  • How floats work

    A mechanism edge from a record to the reasoning beneath it, resting on practice reported consistently across independent sources rather than on experiment.

    • Angling Times — Bauer Media (Specialist angling publication)Relied on for: Contemporary UK coarse, match and lure angling practice as reported by practitioners, including tackle convention.States this directlyCitation checked — the work exists and is described correctly
    • Sea Angler — Bauer Media (Specialist angling publication)Relied on for: Contemporary UK sea angling practice as reported by practitioners, including tackle, bait and lure convention.States this directlyCitation checked — the work exists and is described correctly

  • Sinker, weight and lead: regional vocabulary

    A mechanism edge from a record to the reasoning beneath it, resting on practice reported consistently across independent sources rather than on experiment.

    • Angling Times — Bauer Media (Specialist angling publication)Relied on for: Contemporary UK coarse, match and lure angling practice as reported by practitioners, including tackle convention.States this directlyCitation checked — the work exists and is described correctly
    • Sea Angler — Bauer Media (Specialist angling publication)Relied on for: Contemporary UK sea angling practice as reported by practitioners, including tackle, bait and lure convention.States this directlyCitation checked — the work exists and is described correctly

Rules and access

What these connections rest on (1)

Authoritative guidance — 1 connection

Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.

  • Method and bait restrictions

    A link to a rule CONCEPT rather than to a rule. The record already renders the regulatory-variance notice by its own declaration; this edge says WHICH rules bear on it, which turns a generic warning into a route to the body that holds the current answer.

    • Environment Agency fisheries management, byelaws and rod licensing information — Environment Agency (Government fisheries body)Relied on for: Freshwater and transitional-water fisheries management, the structure of licensing, close seasons and byelaws, and the measures applied to gear, bait, retention and fish movement.States this directlyCitation checked — the work exists and is described correctly
    • Angling Trust guidance for anglers — Angling Trust (Angling or fisheries organisation)Relied on for: Guidance to anglers on fishery rules and conditions of access, including the restrictions individual waters and authorities set.States this directlyCitation checked — the work exists and is described correctly

Environment and conservation

What these connections rest on (1)

Authoritative guidance — 1 connection

Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.

  • Lead in angling

    The restriction is a published instrument and the wildfowl recovery that followed it is documented; the claim here is limited to the existence of the issue and to the physical consequence of substituting materials.

    • The Control of Pollution (Anglers' Lead Weights) Regulations 1986 — The Stationery Office (UK statutory instrument), 1986 (Standards body)Relied on for: The regulatory instrument restricting certain lead weights in angling, and the sizes and circumstances it addresses.States this directlyPassage read and verified
    • Regulation of lead fishing weights results in mute swan population recovery — Biological Conservation, 2019 (Scientific literature)Relied on for: The documented recovery of mute swan populations following restriction of lead angling weights, and the poisoning mechanism behind it.States this directlyCitation checked — the work exists and is described correctly

History and culture

What these connections rest on (1)

Practitioner consensus — 1 connection

Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.

  • The history of match fishing

    A comparison joined to the history that dissolves it. Written where the two things being compared arrived at different times for different reasons, so that 'which is better' turns out to be the wrong question — and refused where the comparison is genuinely contemporary.

    • The Compleat Angler, or the Contemplative Man's Recreation — Richard Marriot, 1653 (Reference work)Relied on for: Seventeenth-century English angling practice including tackle, hooks, lines, baits and artificial flies.States this directlyPassage read and verified
    • Fishers' Craft and Lettered Art: Tracts on Fishing from the End of the Middle Ages — University of Toronto Press, 1997 (Scientific literature)Relied on for: Medieval and early modern angling tracts and the development of tackle, technique and the literature describing them.Background and mechanism onlyCitation checked — the work exists and is described correctly
    • Freshwater Fishing — Macdonald & Jane's, 1975 (Specialist angling publication)Relied on for: Comprehensive angling practice across disciplines, including the development of tackle and the conventions attached to it.States this directlyCitation checked — the work exists and is described correctly

Check the rules before you fish

Fishing laws, bylaws, access rules, seasons, bait restrictions and permitted methods vary by location and can change. Check the current rules from the relevant authority and the water you intend to fish before fishing.

Check with:

  • Current national or regional law for where you are fishing
  • Current local bylaws
  • The relevant fisheries authority
  • The landowner, club or fishery whose water it is
  • Any restrictions specific to the species or the method you intend to use

Sources for this page

  • Coarse Fishing — A. & C. Black, 1912 (Specialist angling publication)Relied on for: Classical coarse angling practice including shotting patterns and the traditional shot size vocabulary.States this directlyCitation checked — the work exists and is described correctly
  • Angling Times — Bauer Media (Specialist angling publication)Relied on for: Contemporary UK coarse and match angling practice as reported by practitioners, including shot and lead convention.States this directlyCitation checked — the work exists and is described correctly
  • IGFA International Angling Rules and World Record Requirements — International Game Fish Association (Angling or fisheries organisation)Relied on for: International angling rules including the unit conventions used for line classes and record measurement.States this directlyPassage read and verified

How FishingHQ labels evidence is explained in the evidence policy.

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