Launching an online course usually starts with one hopeful number — "if even a few percent of my audience buys, I'll clear X dollars" — and ends with a payout that looks nothing like it. The gap is almost never fraud or bad luck; it's the compounding of ordinary funnel math and ordinary fees that nobody adds up in advance. This calculator does that addition for you: audience size, opt-in rate, and conversion rate to find your buyer count, then platform fees, processing fees, and refunds to turn gross sales into what actually lands in your account.
How it works
The engine treats a launch as two multiplications and one subtraction. First, buyers: your audience size times your opt-in rate times your conversion rate, rounded to the nearest whole person, because a launch converts whole buyers, not fractions of one. Second, gross revenue: buyers times your course price. Third, and the part most back-of-envelope math skips, net revenue subtracts your platform's transaction fee and your payment processor's fee from that gross, then applies your expected refund rate on top — refunds come out of what's left after fees, not before, which matches how most platforms actually settle a refunded sale.
Each fee is entered as a straightforward percentage of gross sales. That's a deliberate simplification: real processors like Stripe also charge a small flat fee per transaction (commonly $0.30 in the US), which this calculator doesn't model separately since it's usually a rounding error next to a $50+ course price, but can matter more at very low price points.
Worked example
Take a creator with a 10,000-person audience, a 20% opt-in rate to their waitlist, and a 5% conversion rate from waitlist to buyer, selling a $197 course. They're on a platform charging a 5% transaction fee, their processor takes 3%, and they expect a 10% refund rate.
- Buyers: 10,000 × 20% × 5% = 100 buyers
- Gross revenue: 100 × $197 = $19,700
- Net revenue: $19,700 × (1 − 5% − 3%) × (1 − 10%) = $19,700 × 0.92 × 0.90 = $16,311.60
Fees and refunds together took just over 17% off the top — not from any single line item, but from three modest-looking percentages compounding on each other. That gap only widens on a lower-priced course or a leakier platform.
How to interpret your result
Buyers is the number most worth stress-testing, because it's the product of two rates that are each easy to overestimate. Opt-in and conversion rates vary enormously by traffic temperature: cold traffic landing on a page for the first time often converts at only a few percent at each step, while an engaged, already-warm email list or existing following can convert several times higher. If you've run a launch before, use your own historical rates here instead of a guess — they'll be far more reliable than any industry average, including the ones cited below.
Net revenue is a floor built from the fees and refund rate you enter, not a mirror of your bank statement. It doesn't subtract affiliate commissions on referred sales, income tax on your profit, ad spend or launch costs, or the small flat per-transaction fee most processors charge alongside their percentage — all of those come out of net revenue too, just outside what this tool tracks. Treat the number as "revenue after the costs baked into the sales process itself," not "money you keep."
Methodology & sources
The formulas are buyers = round(audienceSize × optInPercent% × conversionPercent%), gross = buyers × price, and net = gross × (1 − platformFeePercent% − processingFeePercent%) × (1 − refundPercent%).
Platform and processing fee defaults reflect Teachable's own published 2026 pricing: a 7.5% transaction fee on its entry-level Starter plan, 0% on its Builder, Growth, and Custom plans, and a separate payment-processing fee starting at 2.9% + $0.30 per US card transaction through Teachable:pay — see Teachable's pricing page for the current breakdown by plan. Other course platforms (Kajabi, Podia, Thinkific) structure their own fees differently, so swap in your actual platform's numbers rather than assuming these apply everywhere.
Opt-in and conversion benchmarks are genuinely noisy across the industry — one widely cited 2026 roundup puts typical landing-page-to-opt-in conversion around 3-5% (up to 8-15% for top performers) and typical sales-page-to-purchase conversion in the low single digits for courses under $500, with top performers reaching into the double digits; see this online course conversion rate breakdown for the full ranges. Refund rates are just as variable — one course creator's account of running a lenient refund policy describes being comfortable with refund rates up to 7% and cites a hypothetical 5% scenario as a plausible outcome of that policy, in this refund-policy guide — so treat any single number here, including this calculator's defaults, as a starting assumption to replace with your own data as soon as you have it.