📊 ROAS Calculator for Cross-border E-commerce

A free, open-source command-line tool to calculate Return on Ad Spend (ROAS), break-even CPA, profit margins, and multi-channel ad budget allocation — built specifically for cross-border e-commerce sellers.

🌐 Prefer a visual calculator? Use the free online version at kuajingbase.com/en/tools/roas-calculator

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Why This Tool?

Most ROAS calculators online are oversimplified — they only divide revenue by ad spend. But cross-border sellers deal with hidden costs that eat into margins:

• 💳 Payment processing fees (Stripe 2.9% + $0.30, PayPal 3.49%, etc.)
• 📦 International shipping costs ($5–$15 per order)
• 🏷️ Platform commissions (Amazon 15%, Shopify 0%)
• 🔄 Refund/chargeback losses (typically 2–5%)
• 💱 Currency conversion fees (0.5–2%)

This calculator factors in all of these to give you a realistic break-even ROAS — not the fantasy number most tools show.

📖 Learn more about cross-border payment fees: Payment Methods Compared

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Quick Start

Requirements: Python 3.8+

# Clone the repo
git clone https://github.com/reituman602/roas-calculator.git
cd roas-calculator

# Basic calculation
python roas_calculator.py --price 49.99 --cogs 12.00 --shipping 5.50

# With target ROAS and budget simulation
python roas_calculator.py \
  --price 49.99 \
  --cogs 12.00 \
  --shipping 5.50 \
  --target-roas 3.0 \
  --daily-budget 50 \
  --cpc 1.20 \
  --cvr 0.02

# Multi-channel comparison
python roas_calculator.py \
  --price 49.99 \
  --cogs 12.00 \
  --shipping 5.50 \
  --compare

# JSON output (for piping to other tools)
python roas_calculator.py --price 49.99 --cogs 12.00 --json

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Example Output

============================================================
  ROAS CALCULATOR — Cross-border E-commerce Analysis
  https://kuajingbase.com/en/tools/roas-calculator
============================================================

📦 PRODUCT ECONOMICS
  Selling Price:        $49.99
  Total Cost/Unit:      $20.45
  Gross Profit/Unit:    $29.54
  Gross Margin:         59.1%

📊 BREAK-EVEN ANALYSIS
  Break-even ROAS:      1.69x
  Break-even CPA:       $29.54
  (You must spend < $29.54 per sale to profit)

🎯 TARGET ROAS ANALYSIS
  Target ROAS:          3.0x
  Target CPA:           $16.66
  Net Profit/Unit:      $12.88
  Net Margin:           25.8%
  ✅  Profitable! (break-even is 1.69x)

💰 BUDGET SIMULATION (30-day projection)
  Daily Ad Budget:      $50.00
  Expected Daily Sales: 0.8
  Expected Daily Rev:   $41.66
  Expected Daily Profit:$-26.37
  Monthly Profit:       $-791.10
  ⚠️  Projected LOSS — optimize CPC or conversion rate!

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Multi-Channel Comparison

Compare ROAS across Google, Facebook, TikTok, and Pinterest ads in one view:

======================================================================
  MULTI-CHANNEL ROAS COMPARISON
======================================================================

Channel          CPC    CVR      CPA   ROAS   Daily P/L
----------------------------------------------------------------------
Google Ads      $1.50   2.5%   $60.00   0.8x    $-25.18 ❌
Facebook Ads    $0.80   1.5%   $53.33   0.9x    $-22.37 ❌
TikTok Ads      $0.40   1.0%   $40.00   1.2x    $-13.07 ❌
Pinterest Ads   $0.60   2.0%   $30.00   1.7x     $-0.46 ❌

📖 Deep dive into ad strategies: TikTok Ads Guide for Cross-border Stores | Facebook Ads vs TikTok Ads

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All Parameters

Parameter	Default	Description
--price	required	Selling price per unit (USD)
--cogs	required	Cost of goods sold per unit
--shipping	0	Shipping cost per unit
--payment-fee	0.029	Payment processing rate (Stripe: 0.029)
--payment-fixed	0.30	Payment fixed fee per transaction
--platform-fee	0.0	Platform commission (Amazon: 0.15, Shopify: 0)
--refund-rate	0.02	Refund/chargeback rate
--tax-rate	0.0	Tax rate
--target-roas	—	Target ROAS multiplier (e.g., 3.0)
--daily-budget	—	Daily ad spend (USD)
--cpc	—	Average cost per click (USD)
--cvr	—	Conversion rate (e.g., 0.02 = 2%)
--compare	—	Run multi-channel comparison
--json	—	Output as JSON

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Use as a Python Module

from roas_calculator import ProductMetrics, calculate_roas, format_report

product = ProductMetrics(
    selling_price=49.99,
    cost_of_goods=12.00,
    shipping_cost=5.50,
    payment_fee_rate=0.029,     # Stripe
    platform_fee_rate=0.0,      # Shopify (no commission)
)

result = calculate_roas(
    product,
    target_roas=3.0,
    daily_budget=100,
    avg_cpc=0.80,
    conversion_rate=0.02,
)

print(f"Break-even ROAS: {result.breakeven_roas}x")
print(f"Break-even CPA: ${result.breakeven_cpa}")
print(f"Monthly profit at target: ${result.expected_monthly_profit}")

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Common Scenarios for Cross-border Sellers

Shopify Store (Self-hosted)

python roas_calculator.py --price 39.99 --cogs 8.00 --shipping 4.50 \
  --payment-fee 0.029 --platform-fee 0.0 --target-roas 3.0

Amazon FBA

python roas_calculator.py --price 29.99 --cogs 6.00 --shipping 0 \
  --payment-fee 0.0 --platform-fee 0.15 --refund-rate 0.05 --target-roas 4.0

WooCommerce + Stripe

python roas_calculator.py --price 59.99 --cogs 15.00 --shipping 6.00 \
  --payment-fee 0.029 --payment-fixed 0.30 --target-roas 2.5

📖 Need help choosing a platform? Read Shopify vs WooCommerce — Which Is Right for You?

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Related Resources

• 🌐 Online ROAS Calculator — Interactive web version with charts
• 💳 Cross-border Payment Guide — Compare Stripe, Airwallex, Wise, Payoneer fees
• 🏪 Build Your First Store — Step-by-step from zero to first sale
• 🌐 Best Hosting for E-commerce — Cloudways, VPS, and shared hosting compared
• 🛠️ 70+ Cross-border Tools Directory — Every tool tested with real data

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Contributing

Issues and PRs are welcome! If you have ideas for new features (e.g., currency conversion, LTV projection, cohort analysis), please open an issue.

License

MIT License — free to use, modify, and distribute.

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Built with ❤️ by Bob Tong · KuajingBase 跨境基地

A practical resource hub for cross-border e-commerce sellers — store setup, payment solutions, hosting reviews, and growth strategies.