Stuffing Estimator
Pick a shape close to your finished piece, enter its size, and get an estimated weight of polyester fiberfill — so you're not guessing whether that half-used bag will make it through the second leg.
Why this is a volume estimate, not a lookup table
Stuffing amount scales with the volume of the piece, not its stitch count or yarn weight, so this calculator treats your shape as a simple solid — a sphere, a cylinder, or an egg-shaped spheroid — and works out that volume from your measurements, then converts it to a weight using a density that reflects how firmly polyester fiberfill packs at a given tightness. It's necessarily an estimate: two people stuffing the exact same piece to what they'd both call "firm" can land 20-30% apart in actual grams used, since firmness is a feel, not a fixed number. Treat the result as a solid starting point and a shopping-list quantity, not a stop-exactly-here target.
Firmness changes the number more than shape does
The gap between "lightly stuffed" and "firmly stuffed" in this calculator is about double the fiberfill by weight for the same finished size, which matches real experience — firmness is mostly about how much fiberfill you compress into a fixed fabric shell, not a small tweak. If your last project ended up softer or firmer than you wanted at the weight this tool suggests, that's a sign your personal stuffing tension runs lighter or heavier than the "standard" setting assumes; picking the firmness option that matches your usual habit rather than always defaulting to "standard" will get you closer next time.
Stuffing technique matters as much as quantity
Adding stuffing in small pinches throughout the piece as you work — rather than crocheting the whole thing and forcing a mass of fiberfill in through a small closing gap — is what actually produces an even, lump-free result at any of these weights. Pull fiberfill apart into loose, thin layers before adding it rather than pushing in dense clumps; clumped fiberfill is the most common cause of a stuffed piece that looks lumpy or asymmetrical even when the total weight used matches an estimate like this one exactly.