Organic vs Paid Traffic Ratio Calculator

Understanding the organic vs paid traffic ratio — concept and principle

This calculator splits your website sessions into three sources — organic search, paid advertising and everything else (direct, referral, social, email) — and shows each one's share of the total, plus how many organic sessions you get for every paid session. Marketers use it to judge how dependent a site is on ad spend and to track whether SEO and content work is growing the free share over time.

How it is calculated

With organic sessions O, paid sessions P and other sessions R, the total is T = O + P + R.

• Organic share = O ÷ T × 100
• Paid share = P ÷ T × 100
• Other share = R ÷ T × 100
• Organic : paid = O ÷ P, shown as a multiple (×)

All inputs are session counts for the same period and the same property, for example one month in your analytics tool. The three shares always add up to 100%.

The principle

A share is simply a part divided by the whole, so each channel's percentage tells you what fraction of all visits it delivered. The organic-to-paid multiple adds a different view: it ignores the "other" bucket and compares only the two search-driven channels you can most directly influence. Because both measures are ratios, they let you compare months or sites of very different size on the same footing.

Worked example

1. Inputs: organic 18,000, paid 7,000, other 5,000 sessions.
2. Total: 18,000 + 7,000 + 5,000 = 30,000 sessions.
3. Organic share: 18,000 ÷ 30,000 = 60%.
4. Paid share: 7,000 ÷ 30,000 = 23.33%.
5. Other share: 5,000 ÷ 30,000 = 16.67%.
6. Organic : paid: 18,000 ÷ 7,000 = 2.57×, so about 2.6 organic visits arrive for every paid visit.

How to read the result

A high organic share means traffic keeps coming when you pause ads, but it is exposed to search algorithm updates. A high paid share means growth is predictable and controllable yet stops when the budget stops. There is no universal "right" mix. Compare the ratio with your own history and look at conversions and revenue per channel too, since a smaller channel can be the more profitable one.

Common mistakes

• Mixing date ranges or properties, for example organic from one month and paid from another.
• Counting paid social as "paid" in one report and as "social" in another; keep channel definitions consistent.
• Reading a falling organic share as an SEO problem when paid traffic simply grew faster.
• Ignoring untagged campaign links, which often land in direct or referral and distort every share.

Frequently asked questions

What counts as organic traffic?

Visits from unpaid search engine results. In Google Analytics 4 it appears in the default channel group as Organic Search, separate from Paid Search.

What if paid sessions are zero?

The organic : paid multiple cannot be calculated, because it divides by zero. The three shares still work.

Should I use sessions or users?

Either works if you use the same metric for every channel. Sessions reflect visits, users reflect people; a returning visitor can create several sessions.

Sources: Google Analytics Help, "[GA4] Default channel group" definitions