Top diameter, bottom diameter and body height. If the two diameters differ at all, the wrap is a curved fan, not a rectangle. Add about 1/8″ (0.125″) of seam allowance to each side and 1/16″ (0.0625″) of bleed top and bottom.
Take the measurements properly
The single most useful trick here: do not measure the diameter directly unless you own calipers. Finding the exact widest line across a round object with a ruler is guesswork, and a sixteenth of an inch of error at the rim becomes nearly a fifth of an inch of error in circumference.
Instead, measure around and divide:
- Cut a strip of paper and wrap it snugly around the tumbler just below the rim. Mark where it overlaps itself.
- Lay the strip flat and measure to the mark. That is the top circumference.
- Divide by 3.1416. That is your top diameter.
- Repeat just above the base for the bottom diameter.
- Measure the body height — from where the lid seats down to where the base starts to curve in. Not the overall height, and never with the lid on.
Keep the paper strip level. A strip that spirals slightly reads long, and on a tapered vessel it reads long in a way that varies with where you took it.
Why a tapered tumbler is not a rectangle
A tapered tumbler is a cone frustum — a cone with the pointed end cut off. Slit one down the side and flatten it and you do not get a rectangle; you get a curved fan, technically an annulus sector. This is not a subtlety, it is the difference between a wrap that lies flat and one that puckers.
The reason is easy to see in the numbers. The top edge of the wrap has to span the top circumference and the bottom edge has to span the bottom circumference, and on a tapered vessel those are different lengths:
| Blank | Top edge needs | Bottom edge needs | Difference | Fan opens |
|---|---|---|---|---|
| 20 oz skinny (tapered) | 9.30″ | 8.51″ | 0.79″ | 5.6° |
| 20 oz straight-sided | 9.24″ | 9.24″ | 0″ | 0° (a rectangle) |
| 30 oz skinny | 10.59″ | 9.02″ | 1.57″ | 10.8° |
| 40 oz Quencher style | 12.10″ | 9.42″ | 2.67″ | 16.4° |
Read the first row as a warning. On a bog-standard 20 oz skinny, a rectangle cut to fit the top rim is three quarters of an inch too wide at the base. That excess has to go somewhere: it puckers, it overlaps unevenly, or you stretch the material and the artwork distorts. And on a 40 oz Quencher-style body the excess is over two and a half inches, which no amount of careful taping will absorb.
The fan angle column is the other way to see it. The 20 oz skinny only opens about five and a half degrees, which is why people get away with rectangles on it more often than they should — the error is small enough to fudge with a squeegee. By the 40 oz it is sixteen degrees and completely unfudgeable.
The fan's outer arc is exactly π × the top diameter and its inner arc is exactly π × the bottom diameter — each rim's circumference, unrolled. The gap between the arcs is the slant height, √(h² + (rbottom − rtop)²), which is fractionally longer than the vertical height. On a gently tapered tumbler that difference is negligible; on a strongly flared pot it is not.
Seam allowance and bleed
Two different jobs, often confused.
Seam allowance is extra width at each vertical edge, so the two ends overlap slightly rather than meeting exactly. For sublimation, roughly 1/8″ (0.125″) per side is typical. Without it, any rotation while you are taping the wrap down leaves a hairline of bare metal running the full height of the tumbler — the most visible possible failure.
Bleed is extra artwork past the top and bottom edges, usually about 1/16″ (0.0625″), covering vertical drift the same way.
If you are printing vinyl and cutting to the line, you can drop both to zero — the cutter places the edge precisely and an overlap would show as a ridge. The allowances exist for processes where you position by hand.
Common sizes, and why you should still measure
Nominal capacities are marketing names, not specifications. A “20 oz skinny” from one supplier and another from a different one routinely differ by a tenth of an inch — Hogg, Maars, Polar Camel and generic imports all vary. A tenth of an inch is roughly a third of an inch of circumference, which is more than your seam allowance can hide.
So treat published numbers as a starting point for a design you have not bought the blank for yet, and measure the actual blank before you print a run. Measure once per supplier, save the template, and name the file after the supplier rather than the ounce size.
Our Tumbler Wrap Template Generator takes those three measurements and computes the exact fan from the real cone geometry, then hands you an SVG or PNG with the seam and bleed already drawn. It carries presets for the common blanks, but the Custom option is the one to use once you have a tape measure in your hand.
Beyond tumblers
Nothing above is specific to drinkware. Any vessel shaped like a truncated cone unrolls the same way, and the tool handles strongly tapered shapes rather than assuming a gentle 20 oz skinny — plant pots, mixing bowls, cone cups and flared vases all work. The more dramatic the flare, the more the fan curves, and the more obviously wrong a rectangle would have been.
One genuine edge case: a perfectly straight-sided vessel has no taper, so there is no cone apex to measure from and the geometry divides by zero. The correct answer there is simply a rectangle, π × diameter wide by the body height tall.
Frequently asked questions
Should I measure the diameter directly or measure around and divide?
Measure around and divide by π, unless you own calipers. Finding the true diameter of a cylinder with a ruler means finding the exact widest line across a curved surface by eye, and being a little off is easy. Wrapping a paper strip around the rim, marking the overlap and measuring that flat length is far more repeatable.
Do I measure the height including the lid?
No. Measure only the straight body you intend to print on — from just under the rim where the lid seats, down to where the base curves in. Wraps that fail at the top usually do so because the lid seat or a rolled rim was included in the height, so the artwork runs into a curve the material cannot lie flat against.
My blank looks straight-sided. Can I just use a rectangle?
Only if the top and bottom diameters genuinely match when you measure them. Many blanks that look parallel carry a tenth of an inch of taper, which is enough to leave a visible wedge of bare metal at one end. Measure both ends before assuming.
Can I reuse one template across a whole product line?
Only within one blank from one supplier. Two 20 oz skinny tumblers from different suppliers routinely differ by a tenth of an inch — enough to leave a white sliver at the seam. Measure each blank once, save that template, and label it with the supplier rather than the ounce size.
Does this work for plant pots and bowls, or only tumblers?
It works for anything shaped like a cone with the tip cut off. The taper is simply more extreme, so the fan curves harder — a 40 oz Quencher-style body opens about 16°, while a strongly flared plant pot can open far more. The geometry does not change; only the numbers do.
Printing the finished wrap? Our guide to DPI vs PPI covers turning those inch measurements into the right pixel count at export, and if the artwork filling the fan is a repeating pattern rather than a single motif, how to make seamless patterns covers building a tile that repeats without a visible edge.
Figures verified 2026-07-20.
Nominal blank dimensions are those used by our Tumbler Wrap Template Generator, drawn from MakersMath, MakersPage and The Stainless Depot. Arc lengths and fan angles in the table above are calculated from those nominal dimensions using the cone-frustum geometry described in this guide, not measured from physical blanks — suppliers vary, so measure your own.