How to evenly space increases and decreases in crochet

I’ve been writing recently about the different ways you can approach increasing when crocheting in the round.

This got me thinking about how much I used to struggle with working out how many stitches I should crochet between increases (or decreases) to end up with the right stitch count at the end of the round.

So in this post, I want to share a simple tip for working out how to evenly distribute your increases or decreases.

In my post about even circles, I discuss the traditional approach of crocheting your first round with a set number of stitches and increasing by that same number of stitches each round to achieve a flat circle.

Each round you work an increasing number of stitches between the increase to achieve this. Your first increase round you have no stitches between the increases, the next round you have one, then two, then three and so on.

It will look something like this:

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This is great when you are working a flat circle from scratch. But what if you are starting with a larger circle, working in rows, making something shaped or want a smaller or larger number of increases?

Well, however you’re crocheting, the simple bit of maths I’m about to share will explain how to evenly distribute your increases row by row, or round by round.

And there’s a way to do it for decreases too!!

Just before I get started, I should clarify, that for these calculations, an increase is where you work two stitches into one, increasing by one stitch at a time.

Likewise, decreases are where you decrease by 1 a time, working one decrease stitch over two stitches from the previous row or round.

Let’s start with increases.

How to calculate the number of stitches to crochet between increases

Step 1: Decide how many stitches you want at the end of your increase row or round

Step 2: Calculate how many stitches you need to increase by to achieve this (stitches at end of increase round minus stitches on current round)

Step 3: Divide the number of stitches at the end of the increase round by the increase number

Step 4: Subtract 2.

This will give you the number of stitches between your increase.

It’s really that simple!

Here is the calculation for working out the number stitches between increases written as a formula.

Please don’t be scared of the maths or symbols. The big swirly brackets just mean you do that bit first! I’ll talk you through a worked example.

Worked Example

Let’s look at a worked example. I’ve taken some pictures to help illustrate the process. I’ve made a few rows of a swatch with 20 stitches across.

Let’s say I’m working on some shaping and want to increase from 20 to 24 stitches. Let’s plug those numbers in

24 – 20 = 4 (the number of stitches I want to increase by)

24 / 4 = 6

6 – 2 = 4

So I would work 4 stitches, then my increase (2 stitches in the next stitch) all the way across the row.

It looks like this:

I’ve used rows to demonstrate this process because it shows some other aspects you might want to consider.

Once I have worked a couple of non-increase rows after the increase, you can see in the picture below that there is a kind of bump on the left edge of the swatch. This is because I made the last increase right at the end of the row.

A good way of ‘softening’ the impact of increases and smoothing out this bump is to work them one or two stitches in from the end. You get a much subtler graduation.

If you’re working in rounds, this won’t be so noticeable. Though whilst I’m on the topic, it’s good practice to try and stagger your increases so that they are not stacked on top of each other.

You can see where the increases are stacked as you’ll notice that the shape starts to look geometric (like a hexagon or octagon) rather than a circle.

What if the increase number isn’t easily divisible?

As simple as the formula is, there are times when the numbers don’t fit so cleanly and a bit if manipulation is required.

Lets say that I wanted to increase to 22 stitches and I had 18 stitches on the current row. So my increase number would be 4. 22 isn’t easily divisible by 4 so I would end up with a decimal. Not helpful.

My approach to this would be to round down to the nearest multiple of 4, in this case 20, for the calculation:

20 / 4 = 5 and 5 – 2 = 3

So I would work 3 stitches then an increase, 4 times (increasing by 4) which would take up 16 of the 18 stitches.

Then I would need to decide where to put those other two stitches (that I rounded from 22 to 20). In this example, and given what we’ve just discussed about bumps in the edge of the work, I would add the extra two stitches on the end.

Okay, I went off on one a little there. I just wanted to give you an idea of how to wrangle the numbers when they don’t play ball!

Next I’ll show you the calculation for decreases.

How to calculate number of crochet stitches between decreases

This is similar, but subtly different form the increase method.

Step 1: Decide how many stitches you want after your decrease row or round.

Step 2: Calculate the number of stitches to decrease by. (The number of stitches on your existing round minus the number of stitches you want to finish your next round with).

Step 3: Divide the number of stitches on your current round (before you decrease) by the decrease number.

Step 4: Subtract 2. This leaves you with the number of stitches to crochet between decreases.

Here’s the formula for calculating even decreases

Worked example of decreases

So back to my swatch, which now has 24 stitches. Let’s say I want to decrease it to 18 stitches.

24 – 18 = 6 (the number of stitches to decrease by)

24 / 6 = 4

4 – 2 = 2

So in this example, I would work 2 stitches between my decreases across the row to end up with 18 stitches.

The main difference with the decrease calculation is you divide the number of stitches in the current row or round by the decrease number, rather than the resulting one.

Always divide the larger stitch count by the decrease amount.

The same issues apply where the numbers aren’t easily divisible and the same solutions can be used.

I do think that decreases are easier on the eye when worked at the ends of rows, but, again, you can work them a stitch in from the end if you prefer.

You might also find this post on amigurumi tips (which explains invisible increases and decreases) helpful if you’re into aesthetics and getting a smooth finish!

For me, this decrease formula is SO useful when I’m working even decreases.

The increase calculation comes pretty instinctively and I can hold the numbers in my mind. But with decreases, it just bends my brain. So to have a simple formula I can trust is great!

If you are a designer or like to adapt crochet patterns or make them up as you go along then this is definitely one for your took box!

If you like to understand how things like this work, you might be interested in some of my other posts aimed at freestylers and designers.

Happy Hooking

Dx

Materials featured in this post:

Furls’ 4mm Streamline Crochet Hook in Ebony

Furls’ Whims Merino Yarn (DK)

Note that the images were taken of a left handed swatch. The photos of the circles have been flipped for a right handed perspective.