E/MEarnMathby Dynep
The calculator library

Less motivation.
More math.

Every calculator answers one narrow question with transparent formulas and editable assumptions. No signup and no generated income claims.

Sales math

Digital Product Sales Calculator

Required sales, traffic, support load and gross revenue.

 Funnel math

Affiliate Income Goal Calculator

Conversions → clicks → visitors, based on your funnel assumptions.

 Client math

Freelance Income Calculator

Projects, leads, hours and effective hourly income.

 Audience math

Newsletter Revenue Calculator

Paid subscribers, sponsorships and subscriber requirements.

 Order math

Ecommerce Profit Goal Calculator

Contribution per order, orders needed and implied traffic.

 Job math

Local Service Income Calculator

Translate an income target into jobs, qualified leads and delivery hours.

 Decision math

Course ROI Calculator

Cash cost + opportunity cost + expected benefit.

 Unit economics

Break-even Calculator

Month-one and recurring break-even units.

Start with the constraint you are least willing to violate.

The calculators are not eight versions of the same question. Use the income-plan comparison when you are choosing a model; use a focused calculator when you already know the model and need to stress one part of its economics.

  • Time-constrained: compare freelancing, local service, digital product, affiliate, newsletter and ecommerce with explicit monthly-hour assumptions.
  • Demand-constrained: use the conversion/close-rate downside checks to see how quickly required traffic or leads move.
  • Margin-constrained: use ecommerce or break-even to expose costs that topline revenue hides.
  • Learning-investment decision: use Course ROI and rerun it with a materially lower expected profit before paying.
  • Already operating: replace every example default with measured values from your own analytics, invoices or platform reports.

What EarnMath deliberately does not do

It does not invent market conversion rates, promise demand, rank business models by “ease,” or turn a required traffic number into a traffic forecast. The output is only as credible as the assumptions you can defend.

Choose the calculator by the bottleneck you need to test.

Do not start with the business model that sounds most exciting. Start with the constraint most likely to kill the idea. Use the digital-product, affiliate and ecommerce calculators when traffic and conversion are the uncertain bottleneck. Use freelance and local-service calculators when hours, lead flow and delivery capacity are more important. Use newsletter math when audience size and monetization mix are the main questions. Use course ROI before paying for education based on an expected income claim, and use break-even when you already know the unit economics but need the minimum sales volume.

Traffic-limitedDigital products, affiliate, ecommerce
Time-limitedFreelance, local service
Audience-limitedNewsletter
Investment decisionCourse ROI, break-even

One rule applies to every calculator

Defaults are interface examples, not market averages. Replace the assumptions that matter most, then deliberately make them worse. A plan that survives a reasonable downside scenario is more useful than a plan that only works with a precise optimistic input.