An engineer needs to know how to calculate slopes and gradients in differing situations. The most common occurrence of this is working with ramped access to buildings, groundworks, car parks and so on. Slopes can be measured in angles, percentages and ratios. For this post, I will focus on the measurement of slopes in ratios, mainly because gradient ratios are stated in the building regulations.

**How to work out the gradient**

Remember to convert units so they are the same. For example, we have a 10m ramp run and a rise of 500mm. Convert the run to 10,000mm.

**Example:**

We want to work out the gradient of a ramp that has a run of 10m and a rise of 500mm.

Gradient = Run / Rise

Gradient = 10m / 500mm

**Convert the units:**

Gradient = 10,000mm / 500mm

Gradient = 20

Gradient = 1:20

**How to work out the rise**

We want to work out the rise of a ramp that has a run of 5m and a gradient of 1:15.

Rise = Run / Gradient

Rise = 5m / 15

**Convert the units:**

Rise = 5,000mm / 15

Rise = 333mm

**How to work out the run**

We want to work out the run of a ramp that has a rise of 166mm and a gradient of 1:12.

Run = Gradient x Rise

Run = 12 x 166mm

Run = 1,992mm

Run = 1.99m (round up to 2m)

**How to work out slope percentage**

If we want to work out the percentage of a slope, you first must ensure you convert the units so they are the same, similar to working with the ratios above.

Working on one of the previous examples, let’s assume we have a slope that has a run of 10m with a rise of 500mm. First, convert the units.

Rise: 500mm

Run: 10,000mm

Percentage of slope = Rise / Run x 100

Percentage of slope = 500 / 10,000 x 100

Percentage of slope = 5%

I hope you find this post helpful for working out your slopes and ramps!