Hi @cossiblues,
Welcome to the Bunnings Workshop community, it is fantastic to have you with us.
Yes. There are a couple of simple rules of thumb used for steps, so they feel safe and natural to walk.
The riser height, which is the vertical height of each step, should usually be between about 140 and 180 mm. For outdoor garden steps, many people aim closer to 140 mm because it feels easier and is safer in wet conditions. Try to avoid going much over 180 mm because steps start to feel steep and people are more likely to trip.
The tread depth, the part you stand on, is commonly between 280 and 350 mm for outdoor steps. Outdoors, deeper is generally better because you often walk with different footwear, and surfaces can be slippery. If you are using pavers, you often end up with something that suits the module size, like 300 mm or 400 mm, which can work well.
Start by measuring the total rise, which is the vertical height from the lower ground level to the upper ground level. Decide on an approximate riser height that feels right, then divide the total rise by that number. Round the result to a whole number of steps. Once you have the step count, divide the total rise by that number so every riser ends up the same height. Having all risers equal is more important than hitting an exact target height.
Next, look at the horizontal space you have available. This determines the going, or tread depth, of each step. Choose a tread depth that fits comfortably in the space, then check what riser height that combination gives you. If the risers end up too tall or too shallow, adjust the number of steps and recheck.
For example, if the total rise is 720 mm, divide by a target riser height of about 160 mm. That gives 4.5, so round to 5 steps. Divide 720 by 5, and each riser becomes 144 mm. With a 300 mm tread, this produces a comfortable outdoor step, and you can increase the tread depth if you have more room.
If you know your total rise and roughly how much horizontal space you have, those two numbers are enough to work out a clean, consistent set of step heights and tread depths that will feel right.
I'd be happy to have a look at the math if you can advise what your rise and run are.
Let me know if you have any further questions.
Jacob
