The rules for lifting and carrying are intentionally simple. Here is a variant if you are looking for more detailed rules for determining how a character is hindered by the weight of equipment. When you use this variant, ignore the Strength column of the Armor table in chapter 5.

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, 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.
Source: PHB, page 176

Simple right? Let lets check out a quick example while we are at it

Here is our Hero “Average Joe” He has a 10 in Strength!

UnencumberedLight encumbrance Heavy encumbrance Max encumbrance
10*5 = 50 lb 10*10 = 100 lb 10*15 = 150 lb10*30 = 300 lb
0- 50 pounds50.1 – 100 pounds100.1 – 150 pounds 150.1 – 300 pounds
No problemsMovement reduced by 10 feetMovement reduced by 20 feet
ability checks,
attack rolls,
STR, DEX, CON saves
Movement set to 0 feet,

ability checks,
attack rolls,
STR, DEX, CON saves

A good trick to remember is that dropping your backpack is a free action! So put things you can survive without in your backpack and drop it at the start of combat. Just don’t forget to pick it up after!

Next up lets look at Size and Strength.
Larger creatures can bear more weight, whereas Tiny creatures can carry less.
For each size category above Medium Double the creatures carrying capacity.
For a Tiny creature Halve these weights.

So let try changing Joe’s size to see just what that mean

Tiny JoeSmall & Medium JoeLarge JoeHuge JoeGargantuan Joe
carry weight x 0.5 =
25, 50, 75, 150
carry weight x 1 =
50, 100, 150, 300
carry weight x 2 =
100, 200, 300, 600
carry weight x 4 =
200, 400, 600, 1200
carry weight x 8 =

A few of the available player races have a higher weight category than standard medium!

Last up: Push, Drag, or Lift.

You can push, drag, or lift a weight in pounds up to twice your carrying capacity (or 30 times your Strength score). While pushing or dragging weight in excess of your carrying capacity, your speed drops to 5 feet.

This means Medium Average Joe with his 10 Strength can Push, Drag, or Lift 300 pounds at max.

Don’t worry about weight while Pushing or Dragging monsters though, that’s sized based only!