To measure your light level, get a blank sheet of white paper and a ruler.
First, put the blank sheet of white paper in the spot your plant will go. Then hold your hand 12 inches (about 30 centimeters) above the sheet of paper.
If you see a well-defined shadow... you can grow any indoor plant you want to. (Even plants suited to low light levels are only shade "tolerant." Most of them will thrive in cool, bright light.)
If the outline is blurred, you have medium light. Most indoor plants will still do fine, but you'll need to either choose green plants like diefenbacchia or mother in law tongue that enjoy filtered light, or invest in grow lights for to supplement your existing light for succulents, flowering plants, and cacti.
If there is hardly any shadow at all, you have low light. Your plant selection is limited to mostly green leafy indoor plants.
If you do bring in additional lights for your plants - place your hand in front of the light source. If it feels hot it might burn the leaves. As a general rule, if you're comfortable, your plant will be, too.