Tools and Guides to Help You Sell Smarter Online

Free calculators, beginner guides, and selling strategies for eBay, Amazon, Depop, Vinted, and more. Calculate your real profit, find winning products, and start reselling the smart way.

Free calculators and proven guides used by online sellers to estimate fees,
calculate profit, and grow marketplace sales.

Free Marketplace Calculators

Not sure how much profit you’ll actually make? Start with the right tool below and calculate your real earnings before you buy or list any item. Use these tools to avoid costly mistakes and maximise your profit.

Selling On eBay

Calculate fees and final profit instantly.  

Selling On Amazon

Understand margins before you source stock.

Selling On Vinted

Keep 100% of your price — calculate true profit.

Selling On Depop

Keep 100% of your price — calculate true profit. 

Selling On TikTok Shop

Estimate profit for trending products. 

Selling On Etsy

Scale your profit margins before you list.

Profit Calculator ( Most Popular )

Calculate true profit after all costs.

Break-even Calculator

Find the break-even point after fees and costs.

🚀 Not sure where to start?

Fix Common Online Selling Problems

Struggling to get sales? These guides help you solve the most common issues sellers face. TheSellerStack helps you start, grow, and scale your reselling business across multiple marketplaces. Read our Beginner Selling GuidesStart Your Online Selling Journey

STOP THE SLOW MONTHS

Stop Guessing, Start Selling: Data-Backed Solutions for Every Seller Slump.

  • Why your eBay listings get no views (and how to fix it).
  • Why are your items not selling on Vinted?
  • How to increase sales on TikTok Shop.
  • Pricing mistakes that stop you from making sales.

50%

Higher Click Rate

98%

Success Score

TROUBLESHOOT YOUR SHOP

Marketplace Hub

Start and grow your reselling business with step-by-step guides, proven strategies, and the best tools used by successful online sellers.
Displays illustrations of a house pointing to a retail shop, a laptop showing an online store listing clothing, and an old-fashioned turntable. A prominent label reads "START SELLING" and "EASY SETUP.

eBay

The Ultimate Resale Powerhouse: Learn how to start selling on eBay and optimise your listings for more sales.

A sleek, tech-focused promotional banner and infographic for Amazon FBA sellers titled "HIGH-VOLUME HUSTLE: Guides and Tools for Scaling.

Amazon

High-Volume Hustle: Guides and tools to help you sell products and calculate FBA fees.

Tips and strategies for selling clothes successfully on Vinted." On the left, a woman uses her smartphone and a ring light to take high-quality photos of a vintage sweater on a mannequin.

Vinted

Zero-Fee Selling: Tips and strategies for selling clothes successfully on Vinted.

A mirror selfie of a young woman with a mullet hairstyle, wearing a vintage graphic band t-shirt, a black belt, and loose-fitting blue jeans.

Depop

Where Aesthetic Meets Profit: Learn how to grow your Depop shop and attract more buyers.

A photograph of a smiling woman artisan working at a clean, well-lit desk. She wears a brown apron and uses a brush to decorate a ceramic mug. Surrounding her are tools, spools of colorful thread, ceramic supplies, woven baskets, and completed silver jewelry.

Etsy

Craft Your Business: Discover how to sell handmade and vintage products on Etsy.

A promotional infographic for TikTok Shop titled "SELL AT THE SPEED OF SOCIAL: Learn how to sell products through TikTok and grow social commerce sales

TikTok Shop

Sell at the Speed of Social: Learn how to sell products through TikTok and grow social commerce sales.


Why Use TheSellerStack?

  • Free Profit Calculators
  • Practical selling guides
  • Beginner-friendly resources
  • Marketplace fee breakdowns
Thesellerstack

Recommended Tools for Sellers

These tools help you save time, improve your listings, and grow your reselling business faster.

Label Printers

Print shipping labels quickly and streamline your workflow.

Photo & Lighting Setup

Take better product photos that increase conversions.

Listing & Research Tools

Find winning products and optimise your listings.

AI Tools for Sellers

Write better titles, descriptions, and scale faster with AI.


Unlock the potential of your online business today.

Ready to start your first profitable flip?
Use our tools and guides to build your £50-to-£500 stack.
👉 Calculate Your Profit Now

Master the Marketplace

The ultimate weekly digest for the modern UK seller. Latest platform updates, sourcing goldmines, and scaling secrets—zero fluff, all profit. Get new selling guides, fee calculators, and marketplace tips every week.

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