How to crochet a flat circle

There are many crochet patterns which start by creating flat circles (or flat-ish circles at least. From hats, to toys, rugs, baskets, yoke garments and more.

If you like to improvise with crochet projects, then understanding how to create a flat circle by increasing evenly in the round, is a really useful addition to your crochet toolkit.

Once you understand the basic pattern you can use it with any of the basic crochet stitches, and more complex stitch patterns.

In this post, I’m going to explain the basic formula for crocheting a flat circle, then discuss how you need to adjust that depending on which stitch you’re using.

I’ll look at the rule of thumb first and then, for those who like to really dig into a topic, I’ll get into the maths of why it works the way it does and how you can use this to your advantage.

How to crochet a flat circle – the basic pattern

To crochet a flat circle, you start by making a round of stitches into a magic ring or a loop of chains. Each round, you increase evenly by the same number of stitches.

That’s it in it’s simplest terms!

The number of stitches you work into that first round, and increase by each subsequent round, will depend on the stitch you are working.

In the pattern template below, I have replaced this number with an X. After the pattern I will go over what stitch count is suitable (what X is equal to) for different crochet stitches.

The same pattern applies for any of the basic crochet stitches, so I’ve just used the generic term of ‘sts’. You can substitute this with the stitch you want to work.

Abbreviations used in this article – US terms

Chain = ch, single crochet = sc, half double crochet = hdc, double crochet = dc, treble crochet = tr, stitch(es) = st(s), slip stitch = ss

Quick pattern notes

This principle applies whether you turn at the end of the round or work in the same direction (I have excluded instructions for this). It also works if you work in continual rounds of single crochet.

I have excluded the instruction to chain to start the round as the chain number will depend on which stitch you’re working.

Instructions after * should be repeated as instructed.

Basic crochet pattern to make a flat circle

Round 1: Make x sts into a magic ring and join with a ss. x sts

Round 2: 2sts in each st around, join with a ss. 2x sts

Round 3: *2sts in next st, one st in next st; rep from * to end, join with a ss. 3x sts

Round 4: *2sts in next st, one st in each of next 2 sts st; rep from * to end, join with a ss. 4x sts

Round 5: *2sts in next st, one st in each of next 3 sts st; rep from * to end, join with a ss. 5x sts

Continue with this pattern, increasing the number of stitches between the 2st increase by 1 each round. So for Round 6, you would work 2sts in the first st, then one st in the next 4 sts and repeat to the end of the round.

The number of stitches you have at the end of each round will be the number of stitches you started with multiplied by the number of rounds.

As an example, say that you started by working 10dc into a magic ring. Your x would = 10. Your stitch count for Round 1 would be 1x, i.e 10 sts. For Round 2 it would be 2x, i.e. 20 sts, Round 3 it would be 3x, i.e. 30 sts and so on.

How to keep your crochet circle round

You may find that as you work this pattern, your circle turns more into geometric shape with corners rather than smooth curves.

If you don’t turn between rounds, this will be more pronounced. You get this effect because all of your increases are stacked on top of one another.

The simple way to rectify it is to stagger your increases so they no longer stack.

For example, using the 10 dc example, without turning at the end of your round, you could rework the first 5 rows as follows;

• Round 1: 10dc into magic ring, ss to top of first st
• Round 2: Ch2 (doesn’t count as a st), 2dc in each st to end, ss to top of first st
• Round 3: Ch2, starting in first st, *2dc in next st, 1dc in next st; rep from * to end, ss to drop of first st
• Round 4: Ch2, starting in first st, *1dc in next 2 sts, 2dc in next st; rep from * to end, ss to top of first st
• Round 5: Ch2, starting in first st, *1dc in next st, 2dc in next st, 1dc in next 2 sts; rep from * to end, ss to top of first st
• Round 6: Ch2, starting in first st, *2dc in next st, 1dc in next 4 sts; rep from * to end, ss to top of first st

You can see that in each round, the increases are moved around so they are not stacked on top of one another. Round 3 and 6 start with an increase, but round 4 and 5 do not, so you’re not going to get that hint of a corner, but a perfectly round circle..

There are many ways to do this (the above is just one example) and the arrangement will change if you’re turning at the end of your round.

The key thing to remember is; offset the increases each round (so they aren’t stacked) and to keep an equal number of non-increase stitches between the increases.

Oh and check your stitch count at the end of each round to make sure you’ve not added or omitted an increase somewhere along the line.

So now you have the basics, here’s the really important question;

How do you know how many stitches to start with?

(or what x should be)

This is a question I’ve asked myself over and again through my years of making and designing. Never quite having an exact answer was the reason I wrote this blog (so I would make myself find one!)

I’ve come up with two ways to answer it; one is to give you the general rule of thumb and the second is to use maths. (I’ll do both)

Crocheting flat circles with different height stitches

The number of stitches you start with to keep your circle flat will depend on what stitch you are working, more specifically how tall it is.

The taller the stitch, the more of them you will need to work each round to keep the circle flat (the maths will explain why below).

Here’s an example to illustrate this point.

Below are 3 crochet circles I have made using 3 different stitches, sc, hdc and dc (from left to right). In each case I started with 8 sts in the first round and increased by 8 sts each round. I worked 5 rounds following the basic pattern given above.

You can see that in the first example below, where I have started with 8 single crochet, the circle is not flat. It ruffles up because there are too many stitches to ‘fit’ in a flat circle.

In the second example, I have worked the pattern starting with 8 hdc. This one sits pretty flat after 5 rounds. A green tick here!

In the last example below, I have worked the same pattern a third time, starting with 8 dc.

You can see that this circle is starting to curl up. This is because there aren’t enough stitches to stretch around to make a flat circle. Because each stitch is taller, the edge of the circle needs to be bigger. i.e. it needs more stitches to ‘fill’ it.

As you see, the number of stitches you start with (our x value) needs to be appropriate for the stitch height.

How many stitches do you start with to crochet a flat circle?

Note that these are a guideline only. The numbers will vary, mainly depending on your tension and whether you are turning or not turning (as this does impact stitch height)

Different sources may give slightly different guidance to what you see here (though these are not easy numbers to find).

Some of the guides give larger margins than I have here, some give a single definitive number. I have arrived at my recommendations based on my experience and a bit of maths…

The math of crocheting a flat circle

Because I like to look beneath the surface, I want to get into the maths of why I have given these numbers. Understanding why it works the way it does will help you to make adjustments based on your own crochet style.

Just like with my approach to hat sizing, I have gone back to some basic school geometry for this one.

I’m going to walk through an example of how you can calculate the number of stitches you need to start with, based on your gauge. That way you can tailor your project to your own tension.

Definitions:

Diameter (d) = the measurement across the circle at its widest pint

Pi = a standard unchanging mathematical number = 3.14

Circumference = length around the outside edge of the circle (calculated by multiplying the diameter by Pi – sometimes stated as 2Pi r – (where r is the radius) which is the same thing as Pi x d, because the radius is half the diameter)

How to calculate the number of stitches needed for a flat circle

I will use a gauge measurement to calculate the height of each round. Your gauge should be based on a circular swatch, so you might want to use the general guide above to create a swatch to get started.

Step 1: Use the stitch height (based on row gauge) to calculate the diameter and circumference of the circle.

Step 2: Use the stitch gauge to calculate how many stitches are needed to fit into the circle circumference to keep it flat.

Step 3: Use the round count to calculate how many stitches you need to increase by each round.

Worked Example

Lets say we’re working with single crochet in the round and our gauge is 20 sts and 20 rows in 10cm.

I this would suggest that each stitch measures 0.5cm tall and 0.5cm wide.

We’l use that info to calculate how many stitches we would need in a flat circle of 5 rounds.

First off we need to work out the diameter.

Because you’re measuring across the middle circle, 5 rounds would be equivalent to 10 rows.

Based on our gauge, this is going to give us a diameter of 5cm (10 rows * 0.5cm)

Next we can calculate the circumference by multiplying the diameter by Pi:

5 * 3.14 = 15.7cm circumference

Now we know the circumference is 15.7cm, we can use the width of the stitch (0.5cm) to work out how many stitches would be needed to ‘fit’ around the edge of the circle.

To do this, we divide the circumference by the width of each stitch:

15.7 / 0.5 = 31.4 stitches

So we need 31.4 stitches (don’t worry that we’re talking partial stitches at the moment) after 5 rounds to make a flat circle.

Lastly, we use this to calculate what our round multiple should be. (i.e. how many stitches we should start with and increase by.)

To make this calculation, we divide the total number of stitches by the number of rounds:

31.4 / 5 = 6.28 stitches per round

So according to the maths, to create a flat circle with single crochet, you would need to start with, and increase by 6.28 stitches each round.

Obviously we can only work in whole stitches so this would be rounded to 6, which aligns with our rule of thumb mentioned above (yay!)

The maths here is not perfect because if you think about how a stitch works, especially in circles, the stitch may be narrower at the bottom than the top. But it’s a solid start!

How to crochet a flat circle with non standard stitches or stitch patterns

You can use this process with any stitch type, whether it’s another basic stitch, or something more like a bobble or even more complex stitch patterns like shells.

The key is knowing what your gauge measurement is. Then you just follow the maths.

If you’re not familiar with measuring gauge, I strongly recommend you learn the best practices for making and measuring a gauge swatch.

If you like this kind of logical approach but the maths is newer to you, then you might want to check out this post which explains how to use your gauge measurement to calculate your stitch and row counts.

It’s similar to what we have done here, but without the circle part! It’s a really useful skill to have if you like to freestyle it!

If you want to create something using stitch patterns and understand how many repeats to fit into a circle then you can use this process, but you’ll need to have a thorough understanding of stitch multiples.

Crocheting a flat circle using the Pi circle method

So far we have looked at making flat circles by increasing by the same number of stitches each round. This is the most common approach in crochet, but there is an alternative called the Pi circle method, which is more commonly discussed in knitting.

With the Pi circle approach, you double your stitch count on each increase row, but spread your increases out, working non-increase rows in between.

For example, you might start with 6 sts, work 1 non-increase round, double the next round to 12 sts, work 2 non-increase rounds, then double again to 24 sts, work 4 non-increase rounds, double the next round to 48 sts. And so on and so forth.

Because you are doubling your stitch count each round, the number of non-increase rounds between will double in each section.

This is a basic summary of the approach. You can read more about pi circles and pi shawls here.

I’ve never designed an item using this method but it’s something I would like to experiment with in the future.

Why do crochet circles start to ruffle as they get bigger?

If you’re starting with the right number of stitches then your circles should stay flat. Up to a point at least.

If you’ve ever crocheted a large flat circle (maybe a rug or a blanket), you may have noticed that your circle starts to get wavy and you end up with excess fabric.

A couple of years ago, my friend asked me to make her a Christmas Tree Skirt, which I did using a circular pattern. As it got bigger these ruffles started to appear. Ever since then I have been preoccupied with why this happened.

I will be honest. I haven’t come up with a definitive reason why it happens, but here are some ideas.

Firstly, the maths is not precise. In the example, or calculation came to 6.28 stitches needed to keep our single crochet flat, but we were working 6. This small difference may not make a difference after 10 rounds, but after 100 it probably will!

Crochet stitches do not behave as precise units of measure. They are made with love by hand so there is always going to be some variation. Although I like my numbers to add up, I have come to embrace this feature!

This brings me to the next possible reason for this ruffling behaviour.

Stretch and tension.

As you work, the weight of the work will begin stretch the fabric. The curves are more like lines on the rounds so the stitches have more space to spread than in smaller, tighter rounds and your tension will inevitably relax.

Looser tension means that the stitches take up more space, meaning you need less of them to fit in that circle we discussed back at the start. So you end up with excess fabric.

Although it’s useful to understand (for me at least) the reason for the ruffling, what I’m sure you really want to know is: How do you stop it happening?

I have two suggestions here.

First is stop increasing as soon as you notice this ruffle starting to appear. Or, better yet, pull back a couple of rounds so you can catch it before it happens. From then on, only increase every 3 or 4 rounds instead. Eyeball it and adjust it on the fly. It’s not precise I know, but it’s what I can offer!

The second suggestion is blocking. Normally if you stretch out and block your circle, you’ll find that it should flatten out nicely (unless the ruffle is really severe). This article will explain blocking if it’s new to you.

I do love how crochet is a combination of maths and art. One moment you are following the rules happily, then suddenly those same rules stop applying.

It is frustrating and challenging (in a positive way) at the same time.

Most humans find problem solving fulfilling on some level (it’s what our brains evolved to do), even though it doesn’t always feel like it in the moment. But for me, it just adds to the list of reasons crochet ticks my boxes!

I hope your have found this very Doralosophy style explanation useful and now see your simple crochet circles as the little mathematical wonders they are!

Happy Hooking!

Dx