Attribution
Number Pool Calculator: exactly as many tracking numbers as your traffic needs
Size your DNI pool from your own Google Analytics traffic, or from your busiest hour. Enough numbers to give every visitor their own, and none you don't need.
14-day free trial · No credit card · Billed per answered call
Estimate from trafficBuy numbers
Or pick a site like yours
- 100 visitors ÷ (60 ÷ 7 min)11.7 at once
- × 1.3 for headroom15.2
- Rounded up, 2 at least16 numbers
Recommended poolCovers your busiest hour
16 tracking numbers
12 in use at the peak4 headroom
Buy numbers
- Type
- Local
- Area code
- 512
- Quantity
- 1
Quantity set to 16
What is a number pool calculator?
A number pool is the set of tracking numbers that dynamic number insertion shares between your website visitors. Each visitor keeps a number while they browse, so the pool has to cover your busiest hour. The Number Pool Calculator works out that size from your traffic, so every visitor gets a number of their own and you don't pay for spare ones.
With too few numbers, visitors share one and their calls lose their source. A source with only one number is flagged in the app as limited tracking.
How does the number pool calculator work?
Connect your analytics, let Nimbata read the traffic, and buy the pool it recommends.
Connect Google Analytics
Link your GA4 account, then pick the property and how many days back to read.
1Connect
Nimbata reads your traffic
It finds your hourly peak visitors and average session, by channel group or by source / medium.
2Analyze
Get your pool size
Use the recommended pool, and the number search fills in the quantity for you to buy.
3Recommend
The right pool, not a guess
Enough numbers for every visitor, and no budget on spares.
A clear formula
Your busiest hour of visitors, how long each one stays, and a 30% buffer on top. Nothing hidden.
Your real traffic
Sized from your own Google Analytics data over the days you choose, not an industry average.
Sized for each source
See the pool each channel needs, by channel group or source / medium, so paid search never runs short while organic has spares.
No analytics? No problem
Enter your peak hourly visitors and get a recommended pool on the spot.
Know when to add numbers
Google Pool Check keeps comparing each source's traffic with its pool, and a scheduled email can send you its status.
No spare numbers
Buy the pool you need today, then add numbers when your traffic grows.
Know which pools need more numbers
Google Pool Check compares each source's pool with the pool its traffic needs.
This week's pool check
Guessing a pool vs the calculator
A pool that's too small loses sources. One that's too big wastes budget.
| A guess | The Number Pool Calculator | |
|---|---|---|
| Based on | A round number | Your peak traffic and session length |
| Too few numbers | Visitors share numbers, calls lose their source | Covered with 30% headroom |
| Too many numbers | You pay for spares | Only what your traffic needs |
| Per source | One pool for everything | A pool for each channel |
| As traffic grows | You find out from missing sources | Google Pool Check tells you |
Who uses the number pool calculator?
PPC teams
Keep every paid click on its own number so keyword attribution holds.
Agencies
Size a pool for each client from their own traffic.
High-traffic sites
Cover the busiest hour without buying hundreds of numbers.
Small businesses
Start with the few numbers you need and add more later.
Frequently asked questions
How many tracking numbers do I need for DNI?
Enough for the visitors on your site in your busiest hour. The calculator takes your peak hourly visitors, multiplies by a 7-minute average session and divides by 60, then adds 30% headroom. 100 visitors in your peak hour need 16 numbers.
Do I need Google Analytics?
No. Connect Google Analytics 4 to size the pool from your real traffic, or enter your peak hourly visitors yourself.
Can I size a pool for each source?
Yes. With Google Analytics, the calculator recommends a pool for each channel group or for each source / medium.
What happens if my pool is too small?
Visitors share numbers, so some calls can't be tied to the visitor who made them. A source with only one number is flagged in the app as limited tracking.
What happens when my traffic grows?
Google Pool Check keeps comparing each source's traffic with its pool, so you know when to add numbers. A scheduled email can send you its status.
Where do I find the calculator?
In the app, when you buy tracking numbers. Choose to get the size from Google or to estimate it from your traffic.
Still unsure? Talk to a human
Everything you need for call tracking.
Size your pool from your own traffic and track every call to its source.
- 14-day free trial, no credit card
- Billed per answered call
- 24/7 expert support
- No long-term contracts