# Conversion Rate Calculator

> Computes the conversion rate (conversions / visitors × 100), conversions per 1,000 visitors and visitors per conversion, and the number of visitors required to reach a target number of conversions at the same rate.

- Calculator id: `conversion-rate` · Category: Business & Marketing (`business`) · Tool name: `calculate_conversion_rate`
- Canonical page: https://tttkmbb.com/business/conversion-rate · This document: https://tttkmbb.com/business/conversion-rate.md · JSON definition: https://tttkmbb.com/business/conversion-rate.json

## Purpose

Computes the conversion rate (conversions / visitors × 100), conversions per 1,000 visitors and visitors per conversion, and the number of visitors required to reach a target number of conversions at the same rate.

**Use when:** You have visitor and conversion counts for a page, funnel step, email or campaign and need the rate or the traffic a conversion goal requires.

**Do not use when:** You are comparing two variants for statistical significance (use ab-test-significance) or need cost-based metrics such as CPA (use ad-metrics).

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `visitors` | integer |  | required | Number of visitors, sessions, recipients or users exposed to the step. (> 0, max 10000000000000) |
| `conversions` | integer |  | required | Number of them that completed the goal (purchase, sign-up, click). (min 0, max 10000000000000) |
| `target_conversions` | integer |  | optional | Optional conversion goal; returns the visitors needed at the observed rate. (> 0, max 10000000000000) |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `conversion_rate_percent` | number | % | conversions / visitors × 100. |
| `conversions_per_1000_visitors` | number |  | conversions / visitors × 1000. |
| `visitors_per_conversion` | number |  | visitors / conversions (only when conversions > 0). |
| `required_visitors_for_target` | number |  | target_conversions / conversion rate, rounded up (only when target_conversions given and conversions > 0). |

## Formula

`conversion_rate_percent = conversions / visitors × 100; visitors_per_conversion = visitors / conversions; required_visitors = ceil(target_conversions × visitors / conversions)`

## Data Sources

- Google Ads Help – Conversion rate: Definition — https://support.google.com/google-ads/answer/2684489 (reference, retrieved 2026-09-24)
- Wikipedia – Conversion rate optimization — https://en.wikipedia.org/wiki/Conversion_rate_optimization (reference, retrieved 2026-09-24)

Data freshness: `static`. Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output.

## API

- `GET https://tttkmbb.com/api/v1/calculate/conversion-rate?visitors=…&conversions=…`
- `POST https://tttkmbb.com/api/v1/calculate/conversion-rate` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/conversion-rate · OpenAPI operationId `calculate_conversion_rate` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool:  `run_calculator` with `{"calculator_id": "conversion-rate", "inputs": {…}}`

## Example

- 2,500 visitors, 75 conversions, target 300: inputs `{"visitors":2500,"conversions":75,"target_conversions":300}` → `{"conversion_rate_percent":3,"conversions_per_1000_visitors":30,"visitors_per_conversion":33.33,"required_visitors_for_target":10000}`
- 800 visitors, 12 conversions: inputs `{"visitors":800,"conversions":12}` → `{"conversion_rate_percent":1.5,"conversions_per_1000_visitors":15,"visitors_per_conversion":66.67}`

```
GET https://tttkmbb.com/api/v1/calculate/conversion-rate?visitors=2500&conversions=75&target_conversions=300
```

## Limitations

You are comparing two variants for statistical significance (use ab-test-significance) or need cost-based metrics such as CPA (use ad-metrics). All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**Should I count visitors or sessions?**

Use the same unit consistently with the conversion definition: unique visitors for 'share of people who converted', sessions for 'share of visits'. Rates differ between the two.

**How precise is a rate from a small sample?**

A rate from 75 conversions has roughly ±0.7 percentage points of sampling error at 95 % confidence; use margin-of-error to quantify it.

## Related

- [A/B Test Significance Calculator](https://tttkmbb.com/business/ab-test-significance.md) — Test whether two conversion rates differ significantly.
- [Margin of Error Calculator](https://tttkmbb.com/statistics/margin-of-error.md) — Confidence interval for the observed rate.
- [Ad Metrics Calculator (CPM, CPC, CTR, CPA)](https://tttkmbb.com/business/ad-metrics.md) — Cost-based ad metrics such as CPC and CPA.