# Plaintools guides

> The same size bands, fee stacks, and tax splits as the calculators, written out. Estimates only; the live carrier, marketplace, or HMRC page still wins.

Live HTML: https://plaintools.io/guides

These notes use the same formulas as the HTML tools. They are estimates, not a quote from a carrier, marketplace, or tax authority.

## Guides

- [Royal Mail Large Letter vs Small Parcel](https://plaintools.io/guides/royal-mail-large-letter-vs-small-parcel.md): The thickness cap on Large Letter is 25 mm. Miss it and Royal Mail consumer postage steps up to Small Parcel.
- [How Etsy fees work for UK sellers](https://plaintools.io/guides/etsy-fees-uk-sellers.md): The 6.5% transaction fee applies to postage you charged the buyer, not just the item price.
- [Etsy vs Vinted fees for UK sellers](https://plaintools.io/guides/etsy-vs-vinted-fees.md): Same jumper, two fee models: seller commission versus buyer-side protection.
- [Dimensional weight divisors by carrier](https://plaintools.io/guides/dimensional-weight-divisors.md): The divisor, not the tape measure, decides whether a light box is billed as a heavy one.
- [Why Windows cannot open iPhone HEIC photos](https://plaintools.io/guides/why-windows-cannot-open-heic.md): HEIC is a HEIF still. Windows Photos often has no codec. JPEG is the interchange format.
- [GST inclusive vs exclusive (and UK VAT)](https://plaintools.io/guides/gst-inclusive-vs-exclusive.md): Same arithmetic as VAT. India then splits the tax for intra-state invoices.