How long can you keep potatoes before they go bad and you should throw them away?

Store potatoes in a cool (at least room temperature), dry, dark place. A pantry is ideal. Taking the potatoes out of their plastic bag and putting them in a paper one is advisable, given that this further protects them from light, and yet allows them to breathe.

Under the above conditions, you can keep potatoes for about 2 weeks.

However, potatoes can keep for longer -- 4 weeks or more -- if you keep them cooler than room temperature. 7 - 10 Celsius (45-50 Fahrenheit) is ideal.

If the potatoes have started sprouting and softening a little, you can actually still eat them, as long as you remove the sprouts, peel the potato and cook it really well. (boiling them is best)

As long as it's still white, and hasn't started smelling, they won't hurt you.