How we check fit
Methodology updated September 5, 2026
Card Fit Lab compares a chosen card, sleeve configuration and container. The answer depends on the evidence available for that exact setup. We have not physically tested every product or combination in this catalog.
What each label means
| Label | Evidence | What it does not establish |
|---|---|---|
| Published fit report | A linked third party describes the same card size, sleeves, container and card count | A universal capacity or an independent Card Fit Lab test |
| Manufacturer specification | Published dimensions or a compatibility statement, including its conditions | Compatibility with every sleeve brand or production batch |
| Estimate | A calculation from recorded dimensions or a relevant capacity claim | A guaranteed physical fit |
| More information needed | A necessary measurement or relevant report is missing | A failed fit; unknown and won't fit are different results |
Open Why this result? in the checker to see the inputs and source links. When sources disagree, we record the qualification instead of treating the most favorable number as certain.
How deck box estimates work
Estimated stack depth = card count × (card thickness + outer sleeve thickness + inner sleeve thickness).
For sleeved cards, we multiply this by 1.02, a planning allowance for trapped air. The 2% allowance is a model assumption, not a measured constant. Film thickness, printing, foils, sleeve seams, air and compression can change the actual stack.
Where usable interior depth is recorded, a stack exceeding it is marked Won’t fit. Less than 2 mm of remaining depth is marked Tight fit. That threshold is also a planning rule. The diagram uses the same stack and depth as the answer; its box outline is schematic.
A published capacity is not a proven maximum. Without depth data, we label a capacity-based result as an estimate. We do not transfer a sleeve-brand-specific claim to another brand. We also do not scale a single-sleeve capacity into a double-sleeve answer without a measured reference.
How reported fits apply
A successful 100-card report can support a smaller count in the same setup. A failed 100-card report applies at that count or higher, not to a one-card check. A tight-fit report applies only at its reported count. We do not call an observed count the maximum capacity.
Reports must match the card size and exact inner and outer sleeves. For example, DoubleSleeved's combination guide is a third-party test, and its results do not establish how a different inner sleeve will behave.
Binder and toploader checks
Pocket and opening comparisons need both width and height. Toploaders also need a card-thickness limit. The checker uses the dimensions of the outer sleeve when one is selected. A roomy width alone cannot confirm a fit if the height or thickness is missing.
A holder's point rating describes card thickness: 1 point equals 0.0254 mm. It is not the thickness of the holder's walls. Oversleeves and unusually thick, patch or oversized cards require additional information beyond the current tool.
Data corrections
Product records link to their sources. The September 2026 review consolidated duplicate sleeve names and corrected conflicting Katana thickness entries; the revised estimate and its basis appear on the Katana product page.
To report a mismatch, contact us with the product model, card count, sleeve names and a source or measurement. Please distinguish usable interior space from the outside of a box. Never force a lid or a card into a tight holder.
How this site is funded
Some shopping links earn an affiliate commission. The fit calculation does not use commission rates. See the affiliate disclosure and about page.