What Is an Adjustable Measuring Cup and What Does It Measure? | Plunger Cups Explained

An adjustable measuring cup is a reusable vessel with a movable plunger you set to a marked volume, fill, then push to release sticky ingredients straight into a bowl.

Peanut butter and honey break ordinary measuring cups: they cling to the sides, refuse to level, and leave half the dose behind. A plunger that acts like a squeegee fixes that, pushing the whole portion out in one motion. It measures volume — cups, tablespoons, fluid ounces — not weight, and that distinction matters.

How Does an Adjustable Measuring Cup Actually Work?

The plunger is the whole mechanism — slide or turn it to a volume marking, fill to that line, then reverse the motion to empty the cup.

OXO’s sequence: set the knob to the target volume, add the ingredient until it reaches the marking, hold the cup over the mixing bowl, and turn the knob so the plunger pushes everything down and out. The company calls the plunger a squeegee — shortening, molasses, and nut butters come out in one clean pass. Push mechanisms vary (a sliding top disc or a rising bottom plate), but the principle is identical: the platform scrapes the wall as it travels.

What Does It Measure — and What Does It Not?

Adjustable cups measure volume in US customary markings; a 2-cup model typically covers 1/8 cup up to 2 cups. They do not measure weight.

Markings usually include cups, tablespoons, teaspoons, and fluid ounces, with metric conversions on some models. That covers liquids fine but fails on grams, since a cup of flour and a cup of sugar weigh very different amounts. For mass, use a scale. OXO sells both categories: the same catalog listing the $16.99 adjustable cup carries a separate line of measuring scales. They are not interchangeable.

Adjustable Cup vs. Angled Cup: Not the Same Product

OXO’s adjustable liquid cup is distinct from its angled measuring cups, see-through vessels with markings readable from above.

Retailer listings for 2-cup adjustable models cluster between roughly $13 and $18, with professional-series 1-cup models around $14 to $15 — store prices rather than a verified manufacturer figure, so treat them as a range. For a broader look at how leading models stack up, our tested roundup of adjustable measuring cups compares capacities and prices side by side.

Where Adjustable Cups Beat Everything Else

Sticky and semi-solid ingredients are the reason to own one: peanut butter, honey, shortening, syrup, molasses, and thick sauces.

A dry cup leaves a film of peanut butter you cannot fully scrape, so the next tablespoon is short; a glass liquid cup works for honey but wastes whatever sticks to the bottom. The plunger eliminates the residue problem, and less waste means more accurate portions. Liquids work too — the OXO model is rated for both — but that is table stakes; the sticking problem is where the design earns its counter space.

A few cautions. Read the scale carefully before filling, because cups, fluid ounces, tablespoons, and milliliters often share one window. Fill only to the selected line, since excess disrupts the plunger’s travel and throws off volume. Wipe residue off the rim before dispensing. On heat: OXO confirms BPA-free construction and dishwasher safety but does not establish microwave or oven compatibility, so do not assume it — check your model’s instructions.

Do You Need a Scale Instead?

Buy the adjustable cup for sticky volume work and a scale for anything in grams. Most baking benefits from both: a scale settles the flour question volume cannot, since scoop density varies enough to swing a recipe noticeably, while the adjustable cup settles the peanut butter question no scale handles gracefully. The OXO Good Grips 2 Cup Adjustable Measuring Cup product page documents the plunger method and care details in full.