Verystep Guides
The sizes, rules and ideas behind the tools — explained in plain English, one tool at a time.
Every guide here is tied to a single tool on this site. It answers the questions the tool cannot: which size your country actually requires, why the rule exists, where the tool's limits are. No fluff, no sign-up — and each guide ends at the tool itself, so you can act on what you just read.
BMI, BMR and TDEE: Three Numbers, Three Different Jobs
One is a ratio, one is an idling cost, one is a daily total. Compare them as if they were the same kind of number and every one of them will mislead you.
Time Zone Math: Why Your Meeting Keeps Landing at 3 A.M.
Nobody on your team is bad at arithmetic. The offset they memorised quietly expired — that's the whole story behind the 3 a.m. meeting.
JSON Without Tears: Structure, and the Five Errors Everyone Makes
One missing comma can break a whole API call — and the error message will blame the wrong line. Here's the tree underneath the text, and the five mistakes that account for nearly every broken file.
IBAN Explained: How to Read, Check and Trust an IBAN
It's the longest number on the invoice, and two of its digits exist purely to catch your typos. Here's how to read the rest.
Passphrases Beat Passwords: Length, Entropy and Breach Checks
Five ordinary words, chosen at random, outgun the cleverest 8-character scramble you've ever invented — and you won't forget them by Friday.
CBM and Volumetric Weight: How Freight Actually Charges You
Freight charges for space as much as for weight. Two formulas — and one divisor — decide which one your shipment pays for.
ADMT Is Not “AI Regulation”: What California’s Rule Actually Covers
California didn’t regulate “AI”. It regulated one narrow combination — and most tools people worry about never form it.
Your Photos Are Carrying GPS: How to Check and Strip EXIF Data
The picture shows a room, a view, a product. The file underneath it may also be carrying the address.
Shoe Size Conversion US / UK / EU / JP — and Why Brands Disagree
Your foot doesn’t change at the border. The label does — four systems counting the same foot four different ways.
SB 942’s Five Latent-Disclosure Fields, in Plain English
The disclosure your audience never sees is the one California asks for first — five facts, embedded in the file itself.
Ring Size Conversions: US, UK, EU and China Charts Explained
Four alphabets, one finger. Every ring chart on earth is secretly the same number — the millimetres around the inside of the band.
Cron Expressions Explained: Read and Write Any Schedule
Five fields, four symbols, one famous trap. That’s all of cron — and the trap is the part nobody warns you about.
EU AI Act Article 50: Provider or Deployer? The 10-Minute Version
Article 50 doesn’t start with how risky your AI is. It starts with who put it on the market, who runs it — and whether anyone told the person in front of it.
Passport & ID Photo Sizes by Country: mm, Inches and Pixels
Four sizes cover most of the world. The one that surprises people is China — and Canada’s is bigger than everyone else’s.
Remove a Photo Background Without Uploading It: How On-Device AI Works
The remover most people use asks for your photo first and answers second. There is another order: download the AI once, then keep every picture on your own machine.