Here's a rough size guide. Please note all my work is handmade by me so sizes are approximate.
Shown here from left to right;
Large vase - approx 16cm tall (designed for a bunch of daffodils or tulips rather than a full bouquet)
Bud Vase - approx 10.5cm tall (designed for a couple of small stems or small posy)
Teeny Tiny Vase - approx 5cm tall (designed for a single tiny flower, like a daisy)