Is there a way to convert grams to mililiters?

I am traveling to Europe. New airline laws require only a maximum of 100 ml each fluid/gel medications to be carried on board. The several tubes of medication I recently got from my pharmacist are labeled either 15 grams or 30 grams, not in ml's. Since USA is WAY, WAY behind of using the metric system consistently, I have no idea if the 15 gram or the 30 gram tubes exceed the 100 mililiters limit. Can anyone help me? Thanks :)

While everyone that said you can't convert gm. to ml. accurately is correct, it's moot. If your medication is prescription or for a medical purpose, it's exempt from the oz/gr guidelines. Pack it in a clear ziploc bag along with any other prescriptions you may be bringing and offer to take it out at security.

There is no direct conversion because grams is a measure of weight and mililitres is a measure of volume. The weight of a given volume of something with vary with its density.

However as you're taking about relatively small amounts of fluid which are probably quite similar to water in density then you can do an approximate and very simple calculation.

Basically, one of the principles of the metric system is that 1 litre of water weighs 1 kilogram.

Reducing this down means that 1 mililitre of water = 1 gram

So as a good approximation 15 grams = 15 ml and 30 grams = 30 ml

In cases like these, assume 1 gm to be 1 ml. To be on the safe side carry 70ml(gm) so that you would not exceed the 100ml limit.

grams are a measure of mass
ml are a measure of volume

volume = mass / density

thus, to convert, you need to know the density of the fluid.

The density of water is exacly 1 g/ml

so if your fluids are water solutions, the conversion is *approximately* 1g = 1 ml

Gram is to measure weight and milleters are to measure fluids so I dont know.

Get a scale used for baking (I got mine at Target) with a digital read out that lets you convert to metric and just weigh your medications on it.

you can convert grams to milimiters knowing the density of the material or liquid;)
school...