How we calculate TCO (and how to check us)
Every TCO number on this site is produced by a formula you can recompute. This page publishes the formula, the default parameters and a worked example, because a cost model you cannot audit is just a marketing claim.
The model has two sides: a per-row estimate driven by your vendor's MAR rate, and a capacity estimate driven by the plan you would buy. The difference that matters is not the average — it is that the capacity side has a published maximum.
The formula
Per-row model: cost = R / 1,000,000 × p, where R is monthly active rows (inserts + updates + deletes) and p is your vendor's published price per million rows. Add any per-connector or per-environment fees separately.
Capacity model: cost = plan price, bounded by 3 × plan price. There is no row term.
Break-even: set the two equal and solve for R: R* = (plan price × 1,000,000) / p. Above R*, the capacity model is cheaper; below it, the per-row model is. For the Business plan, R* = 1.199e9 / p.
Every input is either published by the vendor or measured in your own environment. Nothing in the model is proprietary.
Worked example
| Parameter | Value | Source |
|---|---|---|
| Monthly active rows (R) | 220,000,000 | Your source system's change statistics |
| Per-million rate (p) | Enter your vendor's published rate | Vendor price list |
| Per-row estimate | R / 1e6 × p = 220 × p | Formula above |
| Bridge Business plan | $1,199 / month | /pricing/ |
| Bridge ceiling | $3,597 / month | 3× cap |
| Break-even rows | 1.199e9 / p | Solve for R |
The example deliberately does not publish a competitor's rate as if it were fixed — rates change and vary by contract. Supply p from the current price list and the arithmetic is reproducible in a spreadsheet.
What the model deliberately excludes
- Operational cost of self-hosting. Servers, egress, on-call and upgrade windows are real. They belong in your comparison, and we list them rather than hide them.
- Engineering time. Running any platform costs engineer hours. The number is yours to supply.
- Switching cost. Migration effort is a one-off and is not netted against subscription savings.
A TCO that only counts licence fees is not a TCO. The calculator lets you add an infrastructure line so the comparison is honest.
TCO questions
Is the calculator's output a quote?
No. It is an arithmetic model using published list prices and the parameters you supply. A quote depends on capacity and services.
Which plan should I model?
Model Standard ($499) if a single node with 4 vCPU fits your peak change rate; model Business ($1,199) if you need a second node, 16 vCPU, a non-production environment or DDL sync.
Does the 3× cap apply to annual plans?
The engine enforces a hard monthly ceiling of three times the plan price. It is a guardrail, not an overage meter.
Can I reproduce the calculation?
Yes — the formula, defaults and break-even expression are all on this page, and the calculator prints its inputs alongside the result.