The rules for lifting and carrying are intentionally simple. Encumbrance is a variant to the rules if you are looking for more detail to determine how a character is hindered by the weight of equipment. When you use this variant, ignore the Strength column of the Armor table.

If you carry weight in excess of 5 times your Strength score, you are encumbered, which means your speed drops by 10 feet.

If you carry weight in excess of 10 times your Strength score, up to your maximum carrying capacity (15 times your Strength score), you are instead heavily encumbered, which means your speed drops by 20 feet and you have disadvantage on ability checks, attack rolls, and saving throws that use Strength, Dexterity, or Constitution.