Free SaaS & startup tools.

28 calculators and tools built to give you a real answer — not a marketing brochure. Numbered, opinionated, and free.

SaaS metrics.

The handful of numbers that decide whether a subscription business scales — MRR, churn, retention, unit economics.

  1. 01

    MRR calculator

    Popular
    Monthly Recurring Revenue, growth rate, and Quick Ratio for SaaS.
  2. 02

    Churn rate calculator

    Popular
    Customer churn, revenue churn, and Net Revenue Retention.
  3. 03

    LTV:CAC ratio calculator

    Popular
    Customer Lifetime Value vs. acquisition cost — the unit economics call.
  4. 04

    CAC calculator

    Customer acquisition cost and payback period.

Financial.

Cash flow, profit, ROI. The numbers that separate businesses that survive from businesses that don't.

  1. 01

    Burn rate calculator

    Monthly burn, runway, and fundraising timeline recommendations.
  2. 02

    Runway calculator

    When you run out of money — and how to extend the runway.
  3. 03

    Cash flow calculator

    Operating cash flow, free cash flow, and liquidity health.
  4. 04

    Break-even calculator

    When revenue covers costs — the line between losing and making money.
  5. 05

    Profit margin calculator

    Gross, operating, and net margin with industry benchmarks.
  6. 06

    ROI calculator

    Popular
    Return on investment, annualized ROI, and multiples.
  7. 07

    Marketing ROI calculator

    ROI, ROAS, CPL, CPA, payback — by campaign.
  8. 08

    SEO ROI calculator

    Popular
    Project month-by-month SEO returns; compare to paid.
  9. 09

    Google Ads budget calculator

    Estimate clicks, conversions, and ROAS for paid search.
  10. 10

    Consulting rate calculator

    Set the right consulting rate based on costs and target margin.
  11. 11

    Freelance rate calculator

    Hourly rate that covers expenses, taxes, and growth.
  12. 12

    Stripe fee calculator

    Popular
    Stripe fees per transaction, reverse, and monthly projection.
  13. 13

    Shopify fee calculator

    Popular
    Compare every Shopify plan at your sales volume.
  14. 14

    Ecommerce profit calculator

    Real margins after COGS, shipping, fees, returns, packaging.
  15. 15

    Startup valuation calculator

    Pre-money valuation via the Scorecard Method.

Startup legal.

Equity splits, vesting, valuations, and conversion math. Cheap to model now, expensive to get wrong later.

  1. 01

    Co-founder equity split

    Popular
    Divide founder equity by contribution, commitment, capital, expertise.
  2. 02

    Vesting calculator

    Vesting schedule with cliff periods and acceleration scenarios.
  3. 03

    Cap table calculator

    Model dilution across multiple funding rounds.
  4. 04

    409A valuation calculator

    Estimate common stock FMV before commissioning a formal 409A.
  5. 05

    SAFE calculator

    Model how a SAFE converts at Series A — cap vs. discount.
  6. 06

    Convertible note calculator

    Note conversion math — interest, discount, cap, ownership.

Hiring.

The real cost of bringing people on — what shows up in budgets, what hides in internal time.

  1. 01

    Employer NI calculator

    Popular
    UK employer NI at the 2025/26 15% rate, with Employment Allowance.
  2. 02

    Cost per hire calculator

    Total cost to fill a role — external spend plus internal time.

Business tools.

Naming, keyword research, project budgeting. Tools for the early decisions where the cost of being wrong is highest.

  1. 01

    Website cost calculator

    Realistic web project cost estimates by type, design, and features.

Need a custom calculator or business tool?

I build custom web applications — calculators, internal dashboards, and business tools in Next.js. Whether it's a public-facing tool to drive leads or an internal app that replaces a brittle spreadsheet, let's talk.

Get in touch

Built by Taro Schenker — full-stack developer who works with startups and local businesses.