Is 25 ml perfume tiny or normal size?

Tiny. Usually the “gift” size. 50–100 is normal. Get eau de parfum, not toilette. Much stronger, use less, lasts longer.

It’s small. Less than an ounce. But, if it is actually perfume/parfum, it isn’t very unusual for a very small size, although usually still larger than 25 ml. The usual sizes for eau de parfum or eau de toilette for women are 1.7 ounces (50ml) and 3.4 ounces (100ml).

25 mL = 0.85 fluid ounces
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It’s a little too small. Get eau de parfum (50ml), it’s better. ;)