In this guide
"How much will it cost to run?" is one of the first questions people ask about a software idea, and one of the hardest to answer from pricing pages. Each tool prices differently: credits, seats, gigabytes, emails, retained users, a percentage of every payment. This guide puts them on one bill and walks it through three stages of a real-shaped product.
The numbers in brief
- Before customers, a small product can run for $0. With first customers and paid tiers, fixed costs settle at about $55–$65 a month.
- At 100 customers ($2,000 a month), the bill is about $167, and card fees are 61% of it.
- At 1,000 customers ($20,000 a month), tools barely move but card fees reach about $1,020, roughly nine-tenths of the bill. You still keep about 94% of revenue.
The product we're pricing
Hypothetical example
A web app sold at $20 a month, paid by card, monthly, mostly by US customers. It has sign-in, a database of text records (no large files), and sends around 40 emails per customer per month: sign-in links, reminders and receipts.
The tools are common first choices: a credit-based host, a hosted Postgres database, a transactional email service, a login service, and a card processor with subscription billing. Swap in your own; the shape of the bill stays the same.
| Line | Tool used for pricing | How it charges |
|---|---|---|
| Hosting | Netlify | Monthly plan with a credit allowance[1] |
| Database | Supabase | Monthly plan, plus disk and compute beyond included amounts[2] |
| Resend | Monthly tiers by emails sent[3] | |
| Logins | Clerk | Free up to 50,000 monthly retained users[4] |
| Payments | Stripe | 2.9% + 30¢ per charge, plus 0.7% for subscription billing[5] |
Stage 1: zero customers
| Line | Plan | Monthly |
|---|---|---|
| Hosting | Free: 300 credits | $0 |
| Database | Free: 500 MB, pauses after a week idle | $0 |
| Free: 3,000 a month, 100 a day | $0 | |
| Logins | Free | $0 |
| Payments | No monthly fee | $0 |
| Total | $0 |
This is the right setup while you're testing the idea. Its weak points are pausing, daily email caps and, on some hosts, terms that exclude commercial use. All three start to matter the moment someone pays. The launch day guide explains when to upgrade.
Stage 2: 100 customers
Revenue: 100 × $20 = $2,000 a month. Emails: about 4,000 a month, past the free monthly limit.
| Line | Plan | Monthly |
|---|---|---|
| Hosting | Pro ($9 Personal also works) | $20 |
| Database | Pro: 8 GB disk, no pausing, daily backups | $25 |
| Pro: 50,000 a month, no daily cap | $20 | |
| Logins | Free tier | $0 |
| Card fees | 100 × ($0.88 + 0.7% billing) | $102 |
| Total | $167 |
You keep about 92% of revenue. The surprise is the shape: four tools together cost $65, card fees alone cost $102. We tell this stage as a story in The $167 bill.
Stage 3: 1,000 customers
Revenue: 1,000 × $20 = $20,000 a month. Emails: about 40,000 a month, still inside the first paid email tier.
| Line | Plan | Monthly |
|---|---|---|
| Hosting | Higher credit tier | $20–$50 |
| Database | Pro, possibly larger compute | $25–$60 |
| Pro, 50,000 a month | $20 | |
| Logins | Still within free tier | $0 |
| Card fees | 1,000 × ~$1.02 | $1,020 |
| Total | ~$1,085–$1,150 |
Tools grew by maybe $50. Card fees grew tenfold. You still keep about 94% of revenue, which is healthy, but the one line worth optimising is now obvious.
What changes if your product is different
A different price
| Price | Revenue at 100 customers | Card fees | Bill with $65 of tools | You keep |
|---|---|---|---|---|
| $10 | $1,000 | $66 | $131 | 87% |
| $20 | $2,000 | $102 | $167 | 92% |
| $50 | $5,000 | $210 | $275 | 95% |
The same tools and the same 100 customers give very different margins. Low prices suffer from the fixed part of each card fee; see card fees at different prices.
A third of customers on yearly plans
If 33 of your 100 customers pay $200 a year instead of $20 a month, their monthly-equivalent fee drops from about $1.02 to $0.63. Total card fees fall from $102 to about $89 a month, and you receive $6,600 up front. Monthly vs yearly works through the trade-offs.
More emails or files
A product sending 300 emails per customer a month crosses into the $90 email tier around 170 customers. A product storing photos pays more for storage and transfer than for everything else combined. Four products, four bills compares these shapes.
Step costs vs per-customer costs
| Grows in steps | Grows with every customer |
|---|---|
| Hosting tiers | Card processing fees |
| Database plan and compute size | Subscription billing fee |
| Email tier, until tens of thousands a month | Tax handling, if charged per transaction |
| Login service, until tens of thousands of users | File storage and transfer, for file-heavy products |
Step costs feel scary because they arrive as a new invoice. Per-customer costs are quieter and end up larger. When you plan pricing, model the right-hand column.
When each line jumps next
- Email moves past the first paid tier at 50,000 a month; the next tier is $90 for 100,000, and extra emails cost $0.90 per 1,000[3].
- Logins start costing past 50,000 monthly retained users, at $0.02 per extra user up to 100,000[4].
- Database disk beyond the included 8 GB costs $0.125 per GB; egress beyond 250 GB costs $0.09 per GB[2].
- Hosting moves to higher credit tiers as traffic and deploys grow; Pro tiers run from 3,000 to 20,000 credits[1].
Where to save first
- Card fees: add a yearly plan and avoid very low prices.
- Price: a small price increase often saves more than every tool optimisation combined.
- Tools: only after the first two. Saving $15 on hosting rarely matters as much as either.
Where cost estimates go wrong
- Budgeting only for tools. Payments are a cost, and usually the biggest one.
- Using revenue instead of customers to estimate email and storage. Usage follows customers and their clients, not dollars.
- Forgetting tax handling if you sell abroad. See Selling abroad.
- Optimising early. At 50 customers, your time is worth more than $20 of hosting.
Questions
Is 92% margin realistic for a small SaaS?
For the direct costs on this page, yes. It doesn't include your time, design tools, a domain, an accountant, or marketing. Those are real costs; they just don't scale with customers in the same way.
What about AI features?
If your product calls an AI model, those calls are a per-use cost that can rival card fees. Price them per customer before you set your price.
When should I revisit these numbers?
At each step: first paying customer, 100 customers, and whenever a provider changes its pricing. We re-check the numbers on this page every quarter.
Put your own price, expected customers and emails per customer into the bill calculator. If card fees come out above half your bill, read card fees and monthly vs yearly before you launch.
What builders are saying
Real public threads on this topic, so you can hear it from people who hit these limits themselves. Summaries are ours; follow the link for the full discussion.
Sources
Checked 14 November 2026. Numbers in brackets in the text point to these sources.
