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Useful calculators for US small businesses.

Use these free tools for everyday business decisions—no signup and no email capture. Built for US small-business owners.

Interest Calculator

Compound interest

About the interest calculator

When to use it

Modelling savings growth, comparing loan offers, or projecting the cost of a director's loan. Pick the compounding frequency that matches the underlying product.

Want a fuller forecast?

Our advisory clients get a full 13-week cash forecast modeled on real bank data. Ask us about the Growth or CFO Partner package.

US SALES TAX LOOKUP

Sales Tax by ZIP Code — US Online Sellers

Use this free US sales tax lookup to quickly find the estimated combined state and local sales tax rate by ZIP code. Enter your sale amount to see the estimated tax due and total price. Built for D2C brands, Shopify sellers, and e-commerce businesses navigating US sales tax compliance.

SALES TAX CALCULATOR FOR ONLINE SELLERS

US Sales Tax Estimate by ZIP Code

5-digit US ZIP code where the sale is delivered

State rates are the base state rate; local rates may apply

City name can help refine estimated local rate

Some categories are exempt or taxed differently by state

Enter a sale amount to calculate estimated tax due and total price

Enter a ZIP code and state, then click Look up sales tax rate to see the estimated combined rate.

Who this tool is for

This sales tax calculator for online sellers is designed for:

  • D2C brands selling physical goods direct to US consumers via their own store
  • Shopify and WooCommerce sellers checking whether they have sales tax nexus in a new state
  • E-commerce businesses pricing products and estimating checkout totals for US buyers
  • US e-commerce sellers managing sales tax across multiple states and marketplaces
  • Bookkeepers and accountants reviewing client sales records for compliance

Nexus & marketplace facilitator rules

US sales tax is governed by individual states, not federal law. Key concepts to know:

  • Economic nexus: Most states require you to collect sales tax once you exceed a threshold (usually $100,000 in sales or 200 transactions in a year in that state), even if you have no physical presence there.
  • Marketplace facilitators: If you sell through Amazon, Etsy, or eBay, the platform typically collects and remits sales tax on your behalf in most states. You may still need to track separately.
  • Origin vs. destination sourcing: Most states use destination-based sourcing (tax is based on where the buyer is), but a few use origin-based sourcing.
  • Product exemptions: Groceries, clothing, and digital goods have varying exemption rules by state.

Need help with sales tax bookkeeping?

US sales tax compliance is complex, especially for growing e-commerce and D2C brands. AccoTiva helps online sellers keep clean records, track nexus thresholds, and stay audit-ready — whether you sell on Shopify, Amazon, or your own store.

MARGIN CALCULATOR

Markup vs Margin Calculator — COGS & Profit

Use this free margin calculator to instantly find your gross profit, profit margin %, and markup % from your cost of goods sold and selling price. Add optional shipping, platform fees, and a desired margin target to model your pricing with confidence. Built for e-commerce sellers, retailers, restaurants, and service businesses.

PROFIT MARGIN CALCULATOR FOR SMALL BUSINESS

Margin & Markup Calculator

$

Your direct product or ingredient cost, before any fees

$

The price your customer pays (excluding any taxes)

$

Per-unit postage, packing, or delivery cost

%

Shopify, Etsy, Amazon, PayPal, Stripe fee as % of selling price

%

Enter a target margin to get a suggested selling price

Enter your cost and selling price, then click Calculate margin & markup to see your profit breakdown.

When to use this calculator

This markup vs margin calculator is useful whenever you need to:

  • Price a new product — work backwards from your target margin to find the right selling price
  • Check your e-commerce margins — factor in Shopify, Amazon, or Etsy fees to see your true take-home profit
  • Calculate restaurant food cost margins — use COGS to confirm your menu pricing covers labour and overheads
  • Compare wholesale vs retail pricing — understand how markup and margin differ at each stage
  • Model platform fee impact — see instantly how a 3–15% marketplace fee affects your bottom line

Why margin matters

Margin and markup are often confused — but they measure very different things:

  • Profit margin is profit as a percentage of revenue. A 40% margin means you keep $0.40 of every $1.00 sold after covering COGS.
  • Markup is profit as a percentage of cost. A 67% markup on a $12 product gives a $20 selling price — but only a 40% margin.
  • Break-even price is the minimum you must charge to recover all costs. Selling below this means a loss on every unit.
  • Target margin pricing lets you work backwards from the profit you need, not just guess a number that “feels right.”

Want cleaner numbers behind your margins?

AccoTiva helps e-commerce brands, retailers, and restaurant operators keep their COGS accurate, their overheads tracked, and their pricing profitable — all year round, not just at year-end.