How do you calculate seam check rate?

Divide completed seam checks by required checks and multiply by 100. With 92 completed against 96 required, the seam check completion rate is 95.8%, leaving a 4.2-point gap to a 100% target.

What is a double-seam teardown?

It is a destructive inspection where a can seam is cut and measured for seam thickness, height, overlap and tightness to confirm a hermetic seal. Teardowns are scheduled at set intervals per seamer head and counted as completed seam checks.

What is a good seam check completion rate?

For a food-safety critical control point the target is 100% — every required check completed. The example 95.8% with a 4.2-point gap means four scheduled checks were missed, which an auditor would treat as a compliance finding.

Why track completion separately from pass/fail?

Because a seam that was never checked is an undetected risk regardless of pass rate. Completion rate proves the schedule was followed; pass/fail proves the seams were good. You need both, and this tool covers the first.

How many seam checks are required per run?

It depends on your seam-check schedule — typically every 30 minutes per seamer head, plus checks at startup and after any adjustment. The example required 96 checks for the run; enter whatever your HACCP plan specifies.

What does the gap to target tell me?

It is the shortfall in percentage points against your goal. The 4.2-point gap in the example flags that completion fell short of 100%, prompting a review of why four scheduled teardowns were skipped.

Bottling, Canning & Filling Lines calculator

Seam Check Rate Calculator

Seam check rate measures how reliably your canning line is performing the scheduled double-seam inspections and teardowns that prove every can is hermetically sealed. Double-seam integrity is a food-safety critical control point — a missed seam check can mean uncontrolled spoilage or recall risk — so quality managers and seamer operators track completion against the required schedule, not just whether checks pass. This calculator turns completed-versus-required counts into a clear percentage and the exact point gap to your target, making compliance visible at a glance. It is the discipline metric that keeps a seamer audit-ready.

What this calculator does

Track completion of required can seam checks, teardowns, or vision inspections during a canning run.
a canning line needs to confirm seam-check coverage before finished cans are released or shipped
It divides completed double-seam checks or teardowns by the required number for the run and multiplies by 100, then reports the gap to your target.

Formula used

Seam check completion rate = completed double-seam checks or teardowns ÷ required seam checks for the run × 100
Gap to target = target - seam check completion rate

Inputs explained

Completed double-seam checks or teardowns:
Required seam checks for the run:
Target seam-check completion rate:

How to use the result

Use it per shift or per production run to confirm the seam-check schedule was followed before product is released, and during audits to demonstrate inspection discipline.
It measures whether checks were done, not whether seams passed; a 100% completion rate with failing seam measurements is still a quality problem this metric will not flag.

Common questions

How do you calculate seam check rate? Divide completed seam checks by required checks and multiply by 100. With 92 completed against 96 required, the seam check completion rate is 95.8%, leaving a 4.2-point gap to a 100% target.
What is a double-seam teardown? It is a destructive inspection where a can seam is cut and measured for seam thickness, height, overlap and tightness to confirm a hermetic seal. Teardowns are scheduled at set intervals per seamer head and counted as completed seam checks.
What is a good seam check completion rate? For a food-safety critical control point the target is 100% — every required check completed. The example 95.8% with a 4.2-point gap means four scheduled checks were missed, which an auditor would treat as a compliance finding.
Why track completion separately from pass/fail? Because a seam that was never checked is an undetected risk regardless of pass rate. Completion rate proves the schedule was followed; pass/fail proves the seams were good. You need both, and this tool covers the first.
How many seam checks are required per run? It depends on your seam-check schedule — typically every 30 minutes per seamer head, plus checks at startup and after any adjustment. The example required 96 checks for the run; enter whatever your HACCP plan specifies.

Last reviewed 2026-05-12.