Hacks: measuring volume visually

Self-tutoring about life hacks: the tutor mentions a couple of thoughts about volume.

Sometimes one might want to measure volume without using a measuring device. What are some ideas?

One technique I use is to relate the volume desired to the total amount in the container. Let’s say you want 60mL from a 500mL container, for instance. That’s 12%, of course – so, just over an eighth. One can visualize the container divided into eight layers, then pour out accordingly. However, this idea is only useful, really, if the container is clear: you have to be able to see how much yet remains to decide if you’ve poured out an eighth of it.

Another technique, if you have a smaller vessel available, is to visually compare it to the amount you’re pouring out. Continuing with the example above, suppose you have a 75mL container that holds something else. You can use it to decide what 75mL looks like – “how much would I pour out to fill that?”

These are a couple of techniques I use to eyeball the volume when I don’t need to measure it exactly, but still want to get close.