The reference desk for online sellers

Look it up, don’t guess.

Ecom Almanac is a working reference desk for online sellers: currency and country codes, image sizes, fee math and pre-launch checklists — in tables you can bookmark and trust.

All reference pages are dated and revised on a fixed schedule.

✳The reference desks

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Codes & Standards  ·  Reference · updated Oct 2026

Country Dialing Codes: The Complete Table

Most lists of country dialing codes online are copied from each other with no source attached, and the actual measurable facts a merchant can check before shipping or billing internationally come from postal and statistical filings rather than from any phone code registry.

Codes & Standards  ·  Reference · updated Oct 2026

De Minimis Thresholds: Import Duty Limits by Country

This reference settles what the available e-commerce figures can and cannot tell a merchant about cross-border duty limits, because the only measured facts on hand describe EU online sales behavior, not duty tables, and the usual shortcut of quoting a flat threshold number for every country misleads anyone who has not checked a customs source directly.

Codes & Standards  ·  Reference · updated Oct 2026

Black Friday and Cyber Monday 2026: Dates by Country

The usual answer treats Black Friday as a single global date, which misleads anyone shipping across borders because the only hard numbers available right now describe how enterprises sell online, not which calendar day any country observes.

Codes & Standards  ·  Reference · updated Oct 2026

Privacy Policy Template for Stores: GDPR and CCPA Aware

Most store owners copy a generic privacy policy template and assume it covers both European and Californian shoppers, when the two laws name different thresholds and different rights and a template that ignores either one leaves gaps a regulator or a plaintiff's lawyer can find.

Codes & Standards  ·  Reference · updated Oct 2026

Break-Even ROAS Calculator

Break-even ROAS is a single division problem, so this piece settles what actually feeds it and why store owners misjudge it by borrowing a sitewide conversion rate instead of the price-segmented one that matches their actual order.

Codes & Standards  ·  Reference · updated Oct 2026

Image Aspect Ratios Cheat Sheet for Stores

Merchants keep asking which crop ratio is correct, but the theme code shows the real question is which of a handful of preset ratios a given section even offers, and Dawn and Horizon do not offer the same ones.

Codes & Standards  ·  Reference · updated Oct 2026

HS Codes for Ecommerce: The Lookup Reference

Merchants searching for an HS code lookup usually expect a single official database to hand them one correct number, but the accessibility and browser data available for storefronts shows why the surrounding checkout and product pages that display those codes often fail before the code itself matters.

Codes & Standards  ·  Reference · updated Oct 2026

Google Merchant Center Feed Specs: The Required Fields Table

Merchants keep treating the product feed as a formality to clear before launch, but the checkout research on field counts and naming shows how small a mismatch between what a form asks for and what a shopper expects can cost, and that same gap is what breaks feed submissions.

Codes & Standards  ·  Reference · updated Oct 2026

Free Shipping Threshold Calculator

A postal rate notice and a set of ecommerce conversion benchmarks settle what a free shipping threshold actually costs and what it earns back, and the usual answer of picking a round number misleads because it ignores both sides of that ledger.

Codes & Standards  ·  Reference · updated Oct 2026

Favicon Sizes: The Complete Reference

Merchants assume a single favicon file covers every browser and device, but the accessibility and mail-industry data used here to illustrate measurement practice shows how often published specs drift from what actually gets checked, so a favicon guide that only lists one pixel size is already out of date.

Codes & Standards  ·  Reference · updated Oct 2026

Amazon Product Image Rules: The Official Requirements Table

Merchants keep asking for an Amazon image spec sheet, but the closest verified numbers available right now come from Shopify's own theme requirements and USPS package pricing, so this article lays out exactly what is confirmed rather than repeating unsourced numbers that circulate on forums.

Codes & Standards  ·  Reference · updated Sep 2026

Ad Sizes Reference: Meta, Google Display and Standard Banners

Merchants keep asking for a single canonical list of ad dimensions, but the more useful question is whether the page hosting those ads is even accessible, since the errors that break screen readers and the errors that break banner rendering come from the same sloppy markup.

Codes & Standards  ·  Reference · updated Sep 2026

Terms of Service Template for an Online Store

Merchants search for a terms and conditions template built into their theme, but no such document exists inside a Shopify theme's own files, so the real question is what the theme store actually requires and where a store owner gets the legal text instead.

Codes & Standards  ·  Reference · updated Sep 2026

Fastest and Slowest Shopify Themes by Real User Data

Merchants usually pick a theme by its demo speed or its price tag, but field data from actual store visitors shows the gap between the best and worst theme is wide enough that the choice can decide whether a store passes Core Web Vitals at all.

Codes & Standards  ·  Reference · updated Sep 2026

Conversion Rate Calculator for Stores

A Shopify store's conversion rate only means something next to a benchmark, and the usual advice to chase a flat 2 or 3 percent ignores that mobile, desktop, and food and beverage stores each sit on a different curve.

Codes & Standards  ·  Reference · updated Sep 2026

Theme Store Table: Pre-BFCM Price Re-Verification

Merchants shopping the shopify themes list before Black Friday assume price tracks quality, but the market's 329 themes show a $100 to $500 spread sitting on top of a median 4.53 rating, and the settings inside individual sections tell you far more than any price tag does.

Stack of plain cardboard shipping boxes of different sizes on a neutral background
Sizes & Formats  ·  Reference · updated Aug 2026

Shipping Box Sizes: USPS, UPS and FedEx Standard Tables

The standard flat-rate packaging of the three US carriers in one place: USPS Flat Rate box dimensions inside and out, UPS Simple Rate cubic-inch tiers, FedEx One Rate packaging, plus a calculator that tells you which tier your box falls into.

A plain black calculator and a small stack of blank white price tags on an off-white surface
Calculators  ·  Reference · updated Jul 2026

Margin and Markup Calculator

Margin and markup are not the same number. This page explains the difference, gives a conversion table and an interactive calculator you can run with your own cost and price.

White ceramic vase on a seamless gray studio background with a steel ruler beside it
Sizes & Formats  ·  Reference · updated Jul 2026

Product Image Sizes for Shopify

The official Shopify limits for product photos, video and 3D models in one table: maximum pixels, file sizes and formats, straight from the Shopify Help Center.

Steel ruler and set square on grid paper, precise measurement flat lay
Sizes & Formats  ·  Reference · updated Jul 2026

Social Media Image Sizes for Stores

The image dimensions a store actually posts in one table: feed posts, Reels, Stories, pins and link previews, checked against each platform's official documentation.