PET Cup Rim Sizes: 78mm, 92mm, 95mm, 98mm — Cup-to-Lid Pairing

PET cold cups come in four standard rim sizes: 78mm, 92mm, 95mm, and 98mm. The rim determines lid compatibility, which determines beverage type (flat vs dome) and operational behavior (no-leak vs spill-prone). Getting cup-to-lid pairing right is the single most important PET cup decision after choosing the volume.

This guide breaks down the rim sizes and how to spec them. For the broader cup category overview see Hot vs Cold Cup Selection.

Rim size reference

When to use which rim

78mm (small)

The 78mm rim corresponds to 12oz PET cups — the smaller end of the cold-cup spectrum. Use cases:

• Coffee shop “small” iced coffee or iced tea
• Kids’ menu drinks
• Sample-size beverages (juice tastings, kombucha samples)
• Bubble tea operations with a “kids” or “small” size

Compatible lids are smaller, which means fewer lid SKUs needed if the operation runs 78mm-only. Some operations standardize on 78mm for simplicity, then offer a larger size in a different format (paper cup for hot, fountain dispense for large fountain drinks).

92mm (mid)

The 92mm rim handles 16oz and 20oz cups. This was the dominant rim size in the 1990s-2000s but has been overtaken by 95mm in volume terms. Many operations still standardize on 92mm because the lid inventory is well-established and the lid options (flat, dome, vented) are mature.

92mm cups are slightly less common than 95mm in 2026 — if you’re starting a new operation, 95mm is the better default for 16-20oz.

95mm (most common)

The dominant rim size in modern fast-casual and bubble tea operations. 16oz, 20oz, and 24oz PET cups all commonly use 95mm rim. The size is wide enough to support:

• Standard flat lids with straw slot
• Dome lids for smoothies and whipped beverages
• Sealing-machine-compatible cups for bubble tea
• Vented lids for cold-brew or carbonated drinks

If your operation does mixed beverage types (iced coffee + smoothies + sodas + bubble tea), standardizing on 95mm gives you lid flexibility across the menu.

98mm (large)

The 98mm rim is for the largest cold cups — 24oz, 28oz, 32oz. Convenience-store fountain drinks (Big Gulp-style), oversize specialty drinks, and large iced coffee at chain coffee shops use 98mm.

98mm bubble tea cups are also common for “large” sizes in operations that want a clearly tiered offering (16oz at 95mm, 24-32oz at 98mm).

107mm (specialty)

The largest standard cold-cup rim, used for beer cups (sometimes called “cold cups” in sports venue / brewery service) and oversize specialty drinks. Rarely used in standard foodservice — limited lid options.

Cup-to-lid pairing as a system

The single biggest mistake in cup procurement: buying cups from one vendor and lids from another, both labeled at the same rim size, then experiencing leaks because the snap geometry doesn’t match.

The fix: Buy cups and lids as a paired system from the same vendor. Same SKU family, designed to fit together. Your lid leak rate drops to near-zero.

Most foodservice distributors carry “paired” cup + lid SKUs explicitly. When pricing, get matched-pair quotes rather than separate cup-only and lid-only quotes from different sources.

Flat vs dome vs vented lids

For each rim size, three lid variants are typically available:

Flat lid (straw slot):

• Lowest cost (~$0.012-0.025/lid depending on rim size)
• Compatible with regular straws and bubble tea straws
• Stacks compactly
• Right for most iced beverages

Flat lid (sip-through, no straw):

• Variant of flat lid with a small drinking hole
• Used in straw-ban markets (CA, OR, WA cities, etc.)
• Same cost as flat-with-slot

Dome lid:

• Extends upward 1-2 inches above the cup rim
• For whipped beverages, smoothies, bubble tea with toppings
• 30-50% higher cost than flat lid
• Lower case-pack (taller lids stack into more compact dome stacks but the cases ship larger)

Vented flat lid:

• Has small pressure-release vents
• For cold-brew or carbonated cold drinks where pressure can build
• Same cost as flat lid

Most operations carry flat lids + dome lids at the same rim size. Vented lids are specialty inventory.

Cost reality

Approximate per-cup and per-lid pricing in 2026:

For a coffee shop doing 200 iced beverages/day at 16oz with flat lids, that’s about $14-20/day, $3,500-5,000/year on cups and lids combined.

Bubble tea operations: cup + sealer integration

Bubble tea operations using heat-sealing machines (instead of snap lids) need a specific cup type — typically 95mm or 98mm rim PET cups designed for film sealing. The cup material and rim geometry must match the sealing machine’s specifications.

See the dedicated Bubble Tea Cups + Sealing Machines cluster for the full integration guide.

SKU consolidation strategy

A common over-procurement pattern: carrying 4 cup sizes × 2 lid types (flat + dome) × 4 rim sizes = 32 potential SKUs. Most operations don’t need this many.

Recommended starter program for fast-casual:

• 16oz cup, 95mm, with matched flat lid (most common iced beverages)
• 24oz cup, 95mm, with matched flat lid (large iced beverages)
• 24oz cup, 95mm, dome lid only when smoothies are on the menu

Three cup SKUs + 2-3 lid SKUs covers ~90% of fast-casual cold beverage menus. Add more only when the menu specifically requires (bubble tea, oversize fountain, specialty).

Decision cheat sheet