Conversion Lag Calculator
Estimate whether your sales cycle fits within each platform's lookback window and get upload frequency recommendations.
What is Conversion Lag?
Conversion lag is the delay between an ad click and the actual conversion event. For online purchases, this might be minutes. For service businesses — HVAC, plumbing, legal, dental — it can be days, weeks, or even months.
Understanding your conversion lag is critical for two reasons:
- Lookback windows: Each ad platform has a maximum time window for accepting offline conversions. If your lag exceeds it, the conversion can't be uploaded.
- Smart Bidding signals: Longer conversion lag means Google's algorithms wait longer to see results from their bidding decisions, which can slow optimization.
Platform Lookback Windows
| Platform | Method | Lookback Window | Upload Deadline |
|---|---|---|---|
| Google Ads | GCLID | 90 days after the click | Google keeps a GCLID for 90 days after the click, so a job closed on day 75 can still be uploaded and the same job closed on day 91 cannot. |
| Google Ads | Hashed email or phone | 63 days after the click | A hashed email or phone matches for 63 days after the click, and from day 64 through day 90 only the GCLID still matches. |
| Meta | CAPI | 7 days after the event | Meta rejects a Conversions API request when the event happened more than 7 days before you send it, so a booking from Monday has to be uploaded by the next Monday, unless it is a physical-store sale, which Meta asks you to send within 62 days. |
| Microsoft Ads | MSCLKID | 90 days | Microsoft Advertising rejects an offline conversion whose time is more than 90 days before the upload and will not count one more than 90 days after the click, so keep the MSCLKID for those 90 days: a sale on August 1 can be uploaded on October 20, and a job that closes 100 days after the click cannot be counted even if you upload it that day. |
| TikTok | Events API | Keep the click ID at least 28 days | TikTok asks you to keep the click ID for at least 28 days and expires it on the attribution window you set, so keep the ID from a March 1 click through at least March 29 and send the job while that window is still open. |
Strategies for Long Sales Cycles
If your sales cycle exceeds a platform's lookback window:
- Upload intermediate events — Send "Qualified Lead" or "Proposal Sent" events that happen within the window
- Send a hashed email or phone with the job — A hashed email or phone matches for 63 days after the click, and from day 64 through day 90 only the GCLID still matches. After day 90, neither one matches.
- Track micro-conversions — Phone calls, form fills, and appointment bookings as earlier signals
- Adjust expectations — For Meta's 7-day window, focus on fast-converting events
For automated lag management, TUOCA's scheduled relays include processing delay buffers and automatic GCLID expiration filtering.
Frequently Asked Questions
Conversion lag is the time between when someone clicks your ad and when they actually convert (book a job, sign a contract, make a purchase). For service businesses, this can range from same-day to 90+ days. Understanding your conversion lag is critical because each ad platform has a maximum lookback window — if your lag exceeds it, you can't upload that conversion.
Google keeps a GCLID for 90 days after the click, so a job closed on day 75 can still be uploaded and the same job closed on day 91 cannot. A hashed email or phone matches for 63 days after the click, and from day 64 through day 90 only the GCLID still matches. After day 90, upload an earlier milestone, such as a qualified lead, that still falls inside one of those windows. Meta rejects a Conversions API request when the event happened more than 7 days before you send it, so a booking from Monday has to be uploaded by the next Monday, unless it is a physical-store sale, which Meta asks you to send within 62 days.
This depends on your conversion lag and volume. For businesses with short sales cycles (same-day to 1 week), daily uploads give Smart Bidding fresh data. For longer cycles, weekly uploads are sufficient. TUOCA's scheduled relays can run hourly, daily, or weekly — with automatic processing delay buffers to avoid CLICK_NOT_FOUND errors.
Meta rejects a Conversions API request when the event happened more than 7 days before you send it, so a booking from Monday has to be uploaded by the next Monday, unless it is a physical-store sale, which Meta asks you to send within 62 days. A 30-day sales cycle still fits if you upload the closed job within a week of closing.