FREE TOOLS FOR MARKETPLACE SELLERS

Know your numbers.
Sell smarter. Across every platform.

HelpSeller helps you calculate real profit, compare pricing decisions, and validate ROI before you spend — with fast inputs and clear outputs.

Know real net profit Include fees, shipping, taxes, and product costs in one result.
Compare price and margin Test pricing scenarios before changing your live listings.
Pick the right next action See outputs that tell you if a product, ad, or seller is worth it.
Learning Hub Ready to start

Start learning marketplace profit fundamentals

Build practical confidence in revenue, costs, fees, net profit, margin, break-even, and ROI.

Completion0%
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Next recommended lessonRevenue
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Tools How it works Guides Pricing
5+
Platforms supported
100%
Free to start
∞
Calculations
// TOOLS

Choose the right calculator
for your next decision.

Each calculator below shows what you enter and what you get back. Start with profit if you are unsure.

Quick recommendation: If this is your first visit, start with Profit Calculator, then use Pricing or ROI to compare scenarios.
Free Tool
Profit Calculator
See true net profit after fees, shipping, taxes, and costs.
You enterSale price, product cost, fee %, shipping, taxes
You getNet profit, margin %, and per-order earnings
Etsy Amazon eBay Gumroad Redbubble
Calculate now →
Free Tool
Pricing Calculator
Set profitable prices instantly with target margin and cost inputs.
You enterCost, fee structure, desired margin, shipping
You getRecommended price and expected margin outcome
Planning Pricing
Calculate now →
Free Tool
ROI Calculator
Estimate ROI before you spend on inventory, ads, or promotions.
You enterInvestment amount, expected return, extra costs
You getROI %, gain/loss estimate, and payback clarity
ROI Ads Products
Calculate now →
Free Tool
Adaptive Learning
Learn revenue, profit, margin, break-even and ROI with adaptive step-by-step tutoring.
You enterShort answers to guided marketplace finance questions
You getAdaptive explanations, mastery tracking, and next lessons
Learning Pricing ROI
Start learning →
BETA
Seller System (Beta)
Experimental standalone calculator workspace. Independent from core app logic and account state.
You enterPrice, costs, platform fee model, margin goal, monthly targets
You getLive panel analysis, scenario comparisons, and projected scale outputs
Experimental Standalone BETA
Open beta tool →
// HOW IT WORKS

Understand what you will enter and what you will get.

Use this flow to move fast: pick a calculator, enter a few numbers, and get decision-ready outputs before you commit money.

STEP 1
Choose your goal

Profit, pricing, ROI, or seller risk. Each tool answers one specific decision.

STEP 2
Enter key inputs

Costs, fees, shipping, taxes, ad spend, or target margin depending on the tool.

STEP 3
Read actionable outputs

Net profit, margin, break-even price, ROI percentage, or a risk score with next steps.

Typical inputs
Cost per itemMarketplace fee %ShippingTax rateAd spend
Typical outputs
Net profitProfit marginRecommended priceROI %Risk level
// GUIDES

Guides

Practical articles and resources to help sellers make smarter business decisions.

// PRICING

Start free. Scale when ready.

All core tools are free to use. Upgrade for history, saved reports, and advanced features.

Free
$0 /month
All core tools, no account needed. Perfect to start.
  • Profit Calculator (all platforms)
  • Unlimited calculations
  • Download results as image
  • Saved history
  • User profile & points
  • Advanced reports
COMING SOON
Starter
$12 /month
For active sellers who want to track and improve their numbers.
  • Everything in Free
  • Save & history (up to 500)
  • User profile & points system
  • Access to all beta tools
  • CSV export
  • Multi-store management
COMING SOON
Pro
$29 /month
For power sellers managing multiple stores and platforms.
  • Everything in Starter
  • Unlimited saves & history
  • Multi-store management
  • Priority access to new tools
  • Advanced analytics dashboard
  • Affiliate program (30% recurring)