Ad Fill Rate Calculator
Calculate ad fill rate, unfilled requests, and estimated revenue lost from ad requests and impressions served — right in your browser.
The Fill Rate Calculator runs entirely in your browser. The ad request, impression, and eCPM numbers you enter are never uploaded to ArrayKit and stay on your device.
Open the eCPM Calculator
About Fill Rate Calculator
The Fill Rate Calculator turns two numbers — ad requests and impressions served — into the metrics ad ops teams check every day. It computes fill rate as served ÷ requests × 100, the count of unfilled requests, and, when you add an eCPM, a rough estimate of the revenue those unfilled impressions left on the table. Use it to sanity-check an ad server or SSP report, compare fill across demand partners, or size the upside of adding a new bidder before you touch a real dashboard. It is built for publishers, yield managers, and ad-tech engineers who want a quick, dependable number without exporting a spreadsheet. Every calculation runs in your browser, so the request and revenue figures you type never leave your device.
Features
- Fill rate percentage from ad requests and impressions served
- Unfilled request count so you see wasted ad calls at a glance
- Optional eCPM input estimates the revenue lost on unfilled impressions
- Copy any result — fill rate, unfilled, or revenue lost — with one click
- Guards against divide-by-zero when ad requests are empty
- Caps fill at 100% when a report lists more served than requested
- Handles large, comma-separated request counts without rounding drift
- Runs entirely on your device with no report data uploaded
How to use the Fill Rate Calculator
- Enter the number of ad requests for the placement or date range
- Enter the impressions served (filled ad calls) for the same window
- Read the fill rate percentage and unfilled request count
- Optionally add an eCPM to estimate the revenue lost on unfilled requests
- Copy the result you need into your report or ticket
Example
Input
ad requests: 100000
impressions served: 65000
eCPM: 2.50
Output
fill rate: 65%
unfilled: 35000
est. revenue lost: $87.50
65,000 of 100,000 requests filled = 65% fill; 35,000 unfilled at a $2.50 eCPM is about $87.50 of potential revenue.
Common errors & troubleshooting
- Fill rate reads over 100% or the tool caps it at 100%. — Impressions served cannot exceed ad requests. Check that both numbers come from the same date range and placement — a served count from a wider window inflates the ratio.
- Fill rate is unexpectedly low across every partner. — Confirm you are counting paid impressions, not passbacks or defaults. Ad server 'requests' often include calls that were never eligible, which drags the ratio down.
- The revenue lost figure looks too high. — Estimated revenue lost assumes every unfilled request would have monetized at your eCPM, which is optimistic. Treat it as a ceiling, not a booked number.
- The calculator shows no result. — Enter non-negative numbers for both ad requests and impressions served. eCPM is optional — leave it blank to see fill and unfilled only.
Frequently asked questions
- What is the ad fill rate formula?
- Fill rate = impressions served ÷ ad requests × 100. If an ad server received 100,000 requests and served 65,000 ads, the fill rate is 65%. The remaining 35,000 are unfilled requests.
- What counts as a good fill rate?
- It depends on format, geo, and demand. Direct-sold and in-app placements often see 80–95%, while long-tail programmatic display can sit far lower. Compare against your own historical baseline and per-partner numbers rather than a universal target.
- How does this tool estimate revenue lost from unfilled requests?
- It multiplies unfilled requests ÷ 1,000 by the eCPM you enter. That is the revenue those impressions might have earned if they had all filled at that eCPM, so treat it as an upper bound rather than a guaranteed amount.
- Why is fill rate capped at 100% here?
- Served impressions should never exceed the requests that generated them. If your report lists more served than requested — usually a mismatched date range or double-counting — the calculator caps fill at 100% and unfilled at 0 so the math stays sensible.
- What is the difference between fill rate and render rate?
- Fill rate measures how many ad requests returned an ad. Render rate (or viewable rate) measures how many of those returned ads actually loaded and were seen. A placement can have high fill but low render if creatives fail to display.
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