Athletic Shoe Sole Thickness Interpreter
Athletic Shoe Sole Thickness Interpreter
Whether a shoe meets World Athletics’ published sole limits: 20 mm for track, jumps and javelin, 40 mm for road running and race walking, and no limit at all for the shot, discus, hammer, cross country or trail. The table changed on 1 November 2024 and the current edition took effect on 20 April 2026.
Is this shoe inside the published limits?
C2.1A, Appendix 2A 38 mm road running shoe with a single rigid structure
Appendix 2, as printed: two rows and nothing else
| Event | Maximum thickness of the sole | Further requirement |
|---|---|---|
| Track Events (excluding Track Race Walking Events), Jumping Events and Javelin Throw Events | 20mm spike shoe or nonspike shoe | For all Jumping Events, the sole at the centre of the athlete’s forefoot must not be higher than the sole at centre of the athlete’s heel |
| Road Running Events, Track and Road Race Walking Events | 40mm | none printed |
What the regulations do not cover, and what still applies
| Event | Sole limit | Why | Still has to be an Approved Shoe |
|---|---|---|---|
| Shot put | none | Regulation 3.3 exclusion | yes |
| Discus throw | none | Regulation 3.3 exclusion | yes |
| Hammer throw | none | Regulation 3.3 exclusion | yes |
| Cross country | none | Regulation 3.3 exclusion | yes |
| Mountain and trail | none | Regulation 3.3 exclusion | yes |
| Javelin throw | 20 mm | named in the 20 mm row | yes |
The dates, which is what makes this a rule worth reading
| Date | What it marks | As the document puts it |
|---|---|---|
| 1 January 2016 | the back stop for old shoes | a shoe “worn before 01 January 2016” is deemed to meet the regulations if it meets the Appendix 2 maxima |
| 1 January 2022 | the start of the current approval regime | approvals “under Technical Rule 5 in force prior to 01 January 2022”, and those “approved under the regulations in force since 01 January 2022” |
| 1 November 2024 | the sole thickness table changed | “an Athletic Shoe with a sole greater than the maximum thicknesses set out in the new sole thickness table … is no longer approved” |
| 19 March 2026 | Council approved this edition | printed on the document |
| 20 April 2026 | this edition took effect | printed on the document |
Twenty millimetres, forty millimetres, and one plate
This page is about athletics — track and field, and road running — whose competition rules, technical rules and scoring tables are published by World Athletics, the body that was the IAAF until 2019. Where a figure below belongs to a particular edition of those rules, the edition is named beside it, because World Athletics revises them and a number quoted without its edition will be wrong for somebody.
Shoe technology is the most argued-about rule change in modern athletics and the rule itself is remarkably short. World Athletics’ Athletic Shoe Regulations, Book C — C2.1A, approved by Council on 19 March 2026 and effective 20 April 2026, carries a sole thickness table of exactly two rows: 20 mm for “Track Events (excluding Track Race Walking Events), Jumping Events and Javelin Throw Events”, spiked or not, and 40 mm for “Road Running Events, Track and Road Race Walking Events”. There is no separate figure for a sprint against a 10,000 m, none for indoors, and none by sex or by age.
Who these regulations actually bind. The Athletic Shoe Regulations govern what may be worn in a World Rankings Competition — Regulation 5.1 requires that “all Athletic Shoes prior to being worn by an Athlete in a World Rankings Competition must be an Approved Shoe”, which means a shoe on World Athletics’ published list. They are not a law about footwear. A parkrun, a club handicap or a charity marathon is not a World Rankings Competition and nobody will measure your midsole at one. What this page tells you is whether a shoe meets the published limits, not whether anybody is going to check.
How the thickness is measured is as load-bearing as the limit, because a manufacturer’s stack height is not the same measurement. Regulation 8.3 takes the sole “at the centre of the forefoot and the centre of the heel”, defining the forefoot centre as “the centre point of the shoe at 75% of its internal length” and the heel centre “at 12% of its internal length”, and measures “the distance between the inside top side and the plane of the outside under side” with the shoe “put on a hard and flat substrate”. The reference sample is a 270 mm shoe — US 8.5, EUR 42, UK 8 — and Regulation 8.4.2 allows a 5% tolerance when the Independent Body examines one. So the rule measures a specific size, at two specific points, from the footbed rather than from the insole.
The plate rule is the other half of the subject and the regulations never use the word carbon. Regulation 8.5.1 says a shoe “must not contain more than one rigid structure if it is a non-spike Athletic Shoe”; 8.5.2 lets that structure “run the full length of the sole or only part of the sole”; 8.5.3 allows a spiked shoe “an additional rigid structure for the purposes of attaching spikes”; 8.5.4 forbids structures that overlap or form “a loop, coil, concertina”; and 8.5.5 forbids any “embedded ‘sensing or intelligent’ technology whatsoever”. The whole of 8.5 is prefaced “Until further notice” and can be set aside by the Chief Executive Officer in exceptional circumstances, which is a candid admission that this part of the rulebook is provisional.
Three things decide whether a shoe may be worn at all, and thickness is only one of them. Regulation 5.1 requires that “all Athletic Shoes prior to being worn by an Athlete in a World Rankings Competition must be an Approved Shoe”, which means one on World Athletics’ published list. A Development Shoe — “an Athletic Shoe which is not intended to and has never been available for purchase” — “cannot be worn in World Athletics Series Events”, needs “prior written approval” anywhere else, may be worn “for a maximum period of 12 months” and “once approved cannot be resubmitted again as a Development Shoe at any time”. And Shoe Control is a real procedure with real limits: Regulation 12.3 says it “must only be conducted after each event the Athlete has competed in” and “must not be conducted in the call room”.
The dated change is the interesting part, and it is unusually clean for this subject. Regulation 8.1 says that “From 1 November 2024, an Athletic Shoe with a sole greater than the maximum thicknesses set out in the new sole thickness table in APPENDIX 2 and in force from the same date, is no longer approved” and “cannot be worn in World Rankings Competitions”. That is a specific date on which a set of existing products stopped being legal. The document does not print the previous table’s figures, so this page does not state what the old maxima were — only that there was a table before this one and that it was replaced on a named day. Being able to say which edition a figure belongs to is the whole reason this plugin prints an edition beside every number, and this is the clearest case of it in the category.
What this page does not do: it does not tell you whether a particular model is on the approved list, because that list is published separately and changes. It rules on the published limits only. For the other equipment rule in this category that turns on exact published dimensions, the throwing sector and circle geometry calculator has the circles and the sector; and for the other thing a reader’s shoes will not change, the wind reading and altitude legality interpreter has the wind rule and the fact that there is no altitude rule at all.
Frequently asked questions
What is the maximum shoe sole thickness in athletics?
40 mm for road running and for race walking on the track or the road, and 20 mm for track events other than race walking, for jumping events and for the javelin — the same 20 mm for a spiked shoe and an unspiked one. Those two rows are the whole of Appendix 2 of World Athletics’ Athletic Shoe Regulations, effective 20 April 2026.
Are there different limits for different track distances?
No. Appendix 2 has two rows and neither splits by distance. There is no separate figure for a sprint, an 800 m or a 10,000 m, and none for indoors. The only split inside the track is race walking, which takes the 40 mm road limit even when it is held on a track.
Which events have no sole limit?
Shot put, discus, hammer, cross country, and mountain and trail. Regulation 3.3 excludes all five from the thickness table and from Regulation 8 entirely. The javelin is not excluded — it is named in the 20 mm row, because it has a run-up.
How is the thickness measured?
At two points on a 270 mm reference shoe: the centre of the forefoot, “at 75% of its internal length”, and the centre of the heel, “at 12% of its internal length”, taken as the distance from the inside top surface to the plane of the outer sole with the shoe on a hard flat substrate. A 5% tolerance applies when the Independent Body examines a shoe. A quoted stack height is not necessarily this figure.
Is a carbon plate legal?
The regulations do not use the word. Regulation 8.5.1 allows a non-spike shoe no more than one rigid structure, which may run all or part of the length of the sole; a spiked shoe may have one more, but only for attaching the spikes. Nothing may overlap, form a loop or coil, or contain embedded sensing or intelligent technology.
When did the limits change?
The sole thickness table was replaced on 1 November 2024, and Regulation 8.1 states that a shoe over the new maxima is “no longer approved” from that date. The edition quoted here was approved on 19 March 2026 and took effect on 20 April 2026. The document does not print the earlier figures, so this page does not state them.
Related calculators
References
- World Athletics. Book C — C2.1A Athletic Shoe Regulations, approved by Council 19 March 2026 and effective 20 April 2026 (read 15 Oct 2026 from the official PDF linked on worldathletics.org; roughly 45,000 to 50,000 characters, READ END TO END and the only rule document in this batch that did not truncate). APPENDIX 2, the Athletic Shoe Sole Thickness Table, has three columns and exactly TWO rows: “Track Events (excluding Track Race Walking Events), Jumping Events and Javelin Throw Events” at “20mm spike shoe or nonspike shoe”, with the note “For all Jumping Events, the sole at the centre of the athlete’s forefoot must not be higher than the sole at centre of the athlete’s heel”; and “Road Running Events, Track and Road Race Walking Events” at “40mm” with no note. Regulation 3.3 excludes from the table and from Regulation 8 the shoes worn in “Shot Put Events, Discus Throw Events, Hammer Throw Events, Cross Country Races and Mountain and Trail Races”. Regulation 8.1 dates the table: “From 1 November 2024, an Athletic Shoe with a sole greater than the maximum thicknesses set out in the new sole thickness table in APPENDIX 2 and in force from the same date, is no longer approved” and “cannot be worn in World Rankings Competitions” — the document does not print the earlier figures. Regulation 8.3, “The thickness of the sole will be measured at the centre of the forefoot and the centre of the heel of the Athletic Shoe”, as “the distance between the inside top side and the plane of the outside under side” with the shoe “put on a hard and flat substrate”; the forefoot centre is “the centre point of the shoe at 75% of its internal length” and the heel centre “at 12% of its internal length”, measured on a 270 mm sample (US 8.5 / EUR 42 / UK 8), with a 5% tolerance at examination by the Independent Body under 8.4.2. Regulation 8.5, “Until further notice” and unless agreed by the Chief Executive Officer: 8.5.1, a shoe “must not contain more than one rigid structure if it is a non-spike Athletic Shoe”; 8.5.2, that structure “can run the full length of the sole or only part of the sole”; 8.5.3, a spike shoe “may … contain an additional rigid structure for the purposes of attaching spikes”; 8.5.4, rigid structures “must not overlap itself or, if in separate parts, overlap each other, must not be a loop, coil, concertina”; 8.5.5, “must not contain any embedded ‘sensing or intelligent’ technology whatsoever”. Regulations 9.1 and 9.2, a shoe “may be so constructed as to provide for the use of up to 11 spikes” and “the number of spike positions must not exceed 11”. Regulation 5.1, “all Athletic Shoes prior to being worn by an Athlete in a World Rankings Competition must be an Approved Shoe”; 4.1, shoes outside Regulation 8 “will be non-compliant”. The “Approved Shoe” definition reaches back to shoes “worn before 01 January 2016”, to approvals “under Technical Rule 5 in force prior to 01 January 2022” and to those “approved under the regulations in force since 01 January 2022”. A “Development Shoe” is “an Athletic Shoe which is not intended to and has never been available for purchase”, “cannot be worn in World Athletics Series Events”, needs “prior written approval” elsewhere, may be worn “for a maximum period of 12 months” and “once approved cannot be resubmitted again as a Development Shoe at any time”. On Shoe Control, Regulation 12.3, it “must only be conducted after each event the Athlete has competed in” and “must not be conducted in the call room”.
- World Athletics. “Book of Rules” index page, worldathletics.org/about-iaaf/documents/book-of-rules (read 15 Oct 2026). The authoritative list of what the rule book currently consists of, and the source of the document codes used on these pages. It lists “C1.1 & C2.1 – Competition Rules & Technical Rules” as a single combined document, last modified 1 July 2026, with no separate Technical Rules file; “C2.1A – Athletic Shoe Regulations (effective from 20 April 2026)”, last modified 19 March 2026, the only entry in the whole list whose effective date is printed in its own title; “C2.1B Mechanical Aids Regulations”, last modified 10 March 2022; and “C1.6 Label Road Race Regulations”, last modified 3 August 2026. Cited because the codes and the dates on these pages are taken from it rather than from a secondary account, and because it establishes that there is no shorter Technical Rules download to try.
- World Athletics. Book C — C1.1 & C2.1: Competition Rules & Technical Rules, the single combined PDF linked from worldathletics.org/about-iaaf/documents/book-of-rules, listed there as last modified 1 July 2026 (fetched 15 Oct 2026). CITED FOR WHAT IT COULD NOT DELIVER, because that is load-bearing: the fetch returns 123,065 characters of readable text and stops inside the Technical Rules at about Rule 5, so Technical Rules 19, 22, 23, 24 and 32 to 34 are NOT in the readable text of the current edition. Its amendment table came through, with effective dates running from 17 December 2020 to 1 July 2026. The page lists C1.1 and C2.1 as one document, so there is no shorter Technical Rules file to fetch instead.