Document-controlled dimensional arithmetic
ISO 2768-1 Documented Tolerance Limit Calculator
Enter a symmetric tolerance copied from the governing drawing, contract or licensed standard. The page calculates arithmetic limits; it does not reproduce, infer or certify the normative ISO 2768 tables.
Documented tolerance arithmetic
Implemented arithmetic—not an ISO table lookup
Upper limit U=N+t
Interval width W=U−L=2t
For a linear value,N and t are in millimetres. For an angular value,N is entered in decimal degrees and t may be entered in degrees,arcminutes or arcseconds;1°=60′=3600″. These equations only propagate a user-documented symmetric tolerance.
NEEDS_LICENSED_SOURCE: the former page reproduced two tolerance tables and selected values automatically. ISO states that ISO 2768-1:1989 contains three tables,while its public Online Browsing Platform exposes only informative material and requires purchase for the full normative content. The old values,boundary wording and omissions cannot be certified from the public card,so they were removed rather than guessed.
ISO 2768-1 status on 12 July 2026
Official records: ISO 2768-1:1989 product page и ISO 2768 Edition2 project page.
Publicly verifiable scope
Сайт official ISO Online Browsing Platform states that Part1 applies to linear and angular dimensions without individual tolerance indications,for parts produced by metal removal or formed from sheet metal. It covers specified categories of linear/angular dimensions and machined assembled parts. It excludes dimensions governed by another general-tolerance standard,auxiliary dimensions in brackets and theoretically exact dimensions in rectangular frames. This is narrower than “all untoleranced dimensions”.
Geometrical-tolerance legacy note
ISO 2768-2:1989 was withdrawn on4February2021;ISO lists it as revised by ISO 22081:2021,which remains current and was confirmed in2026. Do not reuse legacy combined class notation as if Part2 were current;interpret or migrate a legacy drawing through its governing contract and current GPS rules.
Why the former lookup was removed
One default nominal dimension drove both a linear-size table and the shorter-side input for an angular tolerance,even though they are different quantities. At exactly10mm,the code selected the next angular row while the displayed first row said “≤10”. Labels “upper limit” and “lower limit” displayed only +t and −t instead of N+t and N−t. Defaults,presets,local history,unsupported process-to-class advice and “class m when in doubt” guidance were also removed.