Slotly — Appointment & Booking System (PHP + MySQL, Self-Hosted) vs. renting SaaS
Self-hosted appointment booking engineered so it can't double-book.
The subscription math
Slotly — Appointment & Booking System (PHP + MySQL, Self-Hosted) — yours
$39.00
one-time · self-hosted · your data, your server
Available soon — get notified
Calendly — rented
Standard $10/seat/mo, billed yearly
[1]
Break-even:
2 months
of Calendly equals the one-time price.
Assumption: Per-seat pricing - calculator assumes 3 staff seats x $10 = $30/mo (Standard, annual billing).
Acuity Scheduling — rented
Starter $16/mo billed annually ($20/mo billed monthly)
[2]
Break-even:
3 months
of Acuity Scheduling equals the one-time price.
Assumption: Flat per-account Starter tier; annual billing saves 20%.
Savings calculator
SaaS figures use the cited plan price above (see the sources below);
per-seat plans scale by the seat count from the same cited price. This is arithmetic, not a quote.
Also in this category
SimplyBook.me [3]
Basic EUR 11.9/mo billed annually (free tier exists)
Page served EUR prices to our fetch (geo-dependent) - not used in the USD calculator.
Why owning beats renting here
- One payment. No per-month, per-seat, or per-location fees — the license is perpetual.
- Your data stays on your server. Customer records never live in someone else's cloud.
- No plan ceilings. Records, users, and usage are limited by your hosting, not a pricing tier.
- It keeps working if the vendor doesn't. Self-hosted software can't be sunset out from under you.
Fair trade-offs: you host it, you back it up, and updates are yours to apply — see the
product page for honest limitations.
Sources
-
Calendly — price checked 2026-07-05 —
source
“$10 /seat/mo”
-
Acuity Scheduling — price checked 2026-07-05 —
source
“$16/ month”
-
SimplyBook.me — price checked 2026-07-05 —
source
“Basic - 11.9 euro per month (billed annually)”
Competitor prices change — always confirm on the linked page. We only
print figures we could verify on the date shown.