Tim Parker
Writes and maintains BarWeight
Short answer
We do not test equipment. We compute the numbers ourselves, quote specifications out of the published rulebooks and manufacturer spec tables, and cite every source.
What I do here, and what I don't
I write and maintain BarWeight. It is a calculation and reference site: plate math, rep math, bar weights, and straight answers about equipment that has a published specification.
I have not tested any of this equipment. Nobody here has loaded a bar to find out whether it whips, dropped a plate to see if it survives, or measured a knurl with a caliper. There is no test lab behind this site, no rack of samples in a garage, and no rating on this site that came from anybody's hands-on impression. If you want that, you want a review site, and this is not one.
What I do instead is narrower and, I think, more useful: I read the rulebooks and the manufacturer spec tables, I compute the things that can be computed from public data, I show the arithmetic, and I link the source for every figure so you can check it without taking my word for anything. Where a figure is not published anywhere, the page says it is not published rather than filling the gap with a plausible number.
That is the whole basis on which this site asks to be believed. Not a certification, not a career history — the sources are on the page, and you can go and read them.
How the pages are actually built
We compute the strength percentiles ourselves
The standards tables are not copied from anyone. They are computed from the OpenPowerlifting bulk dataset (release 2026-07-18), which the project dedicates to the public domain. Raw lifters only, one best result per lifter so a 30-meet competitor counts once, bucketed by sex and bodyweight — 48 buckets in total, from a pool of 587,379 unique raw lifters. Any bucket that came out under 400 lifters was dropped rather than published thin.
We quote specs out of the rulebooks, not off a blog
The 10 bars and 18 plate entries behind the calculators trace to 10 distinct fetchable sources — the IPF Technical Rules Book, the IWF Technical and Competition Rules, and manufacturer spec tables. Every record names its own source, and where a source does not publish a figure the record says so instead of guessing.
We show the formula and cite it
The one-rep-max tool runs 4 published equations — Epley, Brzycki, Lombardi, O'Conner — and shows each result separately with its original citation rather than blending them into a single house number that nobody can check. Same for plate math: one equation, printed on the page.
We say when the evidence is not there
Of the movement pages, 10 carry at least one cited study and 10 state plainly that no source was verified for them. The upright row page takes no position on shoulder impingement. The hip thrust page says outright that muscle activation is not the same thing as hypertrophy. An empty shelf gets described as an empty shelf.
The pictures and animations are ours too
The equipment images and the animated clips on this site are not photographs and not stock. They are modelled from scratch in three.js to the dimensions in the same spec tables the calculators use, then rendered offline. That is why they can be trusted to show a 45 and a 35 at the correct relative diameter, and it is also why every one of them is captioned as an illustration of a class of equipment rather than a picture of a product you can buy. No render on this site is used as the product image on a gear link.
Where a page shows a human being performing a lift, that is a third-party video embedded from YouTube. We did not make it, we do not host it, and we earn nothing from it. It is credited to its channel on the page.
Corrections
If a number here disagrees with the source it cites, the number is wrong and I want to know. Every figure on this site is traceable to something you can fetch, which means every error on it is findable. The methodology page is the standing statement of what this site will and will not claim.
Questions about who writes this
▶Is Tim Parker a certified coach or a competitive lifter?
No, and this site will never imply otherwise. There is no certification, no coaching credential, no competition record and no years-of-experience figure attached to this name, because none of those has been established. Inventing one to decorate a trust signal is the manipulated-reputation pattern Google's own quality guidance describes, and it would be a straight lie to you. The argument for trusting anything here is the method — every figure is computed from public data or quoted from a cited published source — not the person's résumé.
▶Where do the numbers on this site come from, specifically?
Three places, and each is stated on the page it appears. Competition bar and plate specifications come from the IWF Technical and Competition Rules and Regulations. Strength percentiles are computed by us from the public-domain OpenPowerlifting bulk dataset — 587,379 unique raw lifters — which is why we can publish them rather than reprinting somebody else's copyrighted table. Equipment specifications are read off each product's own listing or manufacturer sheet, with the read date on the card. Across the bar and plate data there are 10 distinct source documents.
▶Why do some exercise pages say there is no study?
Because for many popular lifts there genuinely is not one worth citing. 10 of the movements on this site carry at least one cited electromyography source; 10 carry none and say so in plain language on the page, describing standard functional anatomy instead. Publishing an invented percentage would be easy and would look more authoritative. Saying the shelf is empty is the honest version, and it is the editorial position of the whole site.
▶How do I report an error?
Every figure on this site is traceable to something you can fetch yourself, which means every error on it is findable. If a number disagrees with the source it cites, the number is wrong. The calculators are covered by a test suite of hand-computed cases, so a reported arithmetic error becomes a failing test before it becomes a fix — which is also why a fix cannot quietly break something else.