🧶 Knitting for a certain fit is only as good as your measurements—and luckily, it doesn’t take much to get them right. And here’s the best part: knitted fabric is wonderfully forgiving. It stretches, shifts, and settles with wear, so your measurements don’t need to be perfect to feel great. Think of them as a starting point, not a final judgment.
🧵 Before You Start Measuring… There are two great ways to gather your measurements:
- Measure a garment you love — Laying a favourite sweater flat is often the easiest way to get reliable numbers, especially for widths and lengths.
- Measure yourself — This can be more personalized, especially if you want to adjust for unique proportions or experiment with fit. If possible, ask a friend to help—some areas are much easier and more accurate with a second pair of hands.
📝 Tip: No matter how you take your measurements, jot them down and keep your notes handy—you might find yourself referring back often as you experiment and fine-tune your fit.
📍 Key Measurements Explained
🧶 Bust Circumference (Full Chest)
- Where: Around the fullest part of the chest—adjust the number for the desired ease.
- Tip: 💡 Keep tape level and snug, but not tight.
- Why: Determines body width and balance of front/back stitch counts.
🎯 Upper Arm Circumference
- Where: Around the widest part of your bicep—adjust for ease.
- Tip: 💡 Let your arm hang naturally at your side.
- Why: Sets sleeve width and underarm shaping.
🧤 Wrist / Lower Arm Circumference
- Where: Around your wrist or the the part of your lower arm where the sleeve ends—adjust for ease. The cuff length is not included in this measurement.
- Why: Helps shape the sleeve taper.
🎯 Neckline Circumference
- Where: Around the base of the neck, following the path where the neckline would sit before any shaping.
- Tip: 💡 Use a piece of yarn or string to trace a simple neckline shape, then measure its full length.
- Tip: 💡 Not sure how wide to make your neckline? For a collar that sits close to your neck, use your neck circumference as a guide. The knitting will stretch over your head, but, to be sure, you can rather use your head circumference as a guide—it ensures the sweater can slip on easily. Also, any neckline shaping worked in the pattern will enlarge the opening, so a smaller initial opening can work well!
- Why: Helps determine the stitch count for the neckline opening and how many stitches to reserve for shaping styles like crew or V-necklines.
🎯 Neckline Depth
- Where: From the base of the neck (where your chosen neckline would naturally sit—laying flat across the neck, before any shaping or collar is added) down to the desired lowest point at centre front.
- Tip: When measuring, imagine the neckline sitting evenly around the neck—without the back riding up or the front pulling down. The front point will often be roughly parallel to the shoulder seam. Keep in mind that adding a collar will raise the neckline inward toward the neck, depending on how deep or tall the desired collar is.
- Why: Helps shape the overall look and feel of the sweater—whether you want cozy and high or open and breezy.
Common Depths:
| Style | Typical Depth | Notes |
|---|---|---|
| Crew Neck | 2–3.5″ (5–9 cm) | Classic, sits high on the chest |
| V-Neck (Shallow/Standard) | 3.5–4.75″ (9–12cm) | Subtle/Classic dip, great for layering |
| V-Neck (Deep) | 5–9″ (13-23 cm) | Bold and elongating |
📐 Armhole Depth
- Where: From the top of your shoulder (at the sweater neckline basically, before the edging) straight down to the point under your arm—adjust for ease.
- Tip: 💡 You can also measure from a well-fitting sweater or shirt.
- Why: Affects sleeve angle and yoke shaping depth.
🧵 Underarm Width (Underarm Cast-On)
- Where: Horizontal space from the front of the underarm to the back, just under where sleeve and body connect.
- Tip: 💡 Typically between 1.5″–3″ (4cm-8cm); choose less for a closer fit (less bulk in the armpit area), more for mobility.
- Why: Determines stitches added (cast-on) when you separate sleeves.
👕 Body Length Below Armhole
- Where: From the base of the armhole (where sleeve and body meet at the underarm) to the bottom of the sweater. Do not include the bottom edging for the calculator measurements.
- Tip: 💡 Customize based on style—cropped, hip-length, or tunic.
- Why: Determines the number of rows left to knit after doing all the shaping for the yolk portion.
👕 Full Body Length
- Where: From the top of the shoulder (at the sweater neckline basically, before the edging) to the bottom of the sweater. Do not include the bottom edging for the calculator measurements. Note that you may want to take into account that the weight of the sweater, especially with a loose or ‘airy’ gauge, can lead to the the sweater stretching a bit further down than the actual knitted length.
- Tip: 💡 Customize based on style—cropped, hip-length, or tunic.
- Why: Determines the total number of rows to knit for the sweater length.
Sleeve Length
- Where: From the base of the armhole (where sleeve and body meet at the underarm) to wrist. Do not include the cuff edging for the calculator measurements.
- Note: The amount of positive ease in your bust circumference affects the meeting point on the sweater of sleeve and body compared to your actual underarm. You may consequentially want to measure a bit down your arm away from your underarm when taking this measurement on your own body; a measurement down of about 1/4 of total positive ease added to the bust circumference. For example, if you have added 4 inches of positive ease to your bust measurement, start your sleeve length measurement 1 inch away from your underarm when measuring toward your wrist (the result will be that your sleeve measurement will be a bit shorter).
- Why: Determines number of rows for the sleeve.
Head Circumference
- Where: Measure around the widest part of the head—typically just above the eyebrows and ears, circling horizontally around the back.
- Tip: 💡 For a comfortable fit with gentle stretch, most knitters use a circumference that’s about 10-15% smaller than the actual head measurement—this is called negative ease. For example, if your head measures 56 cm, a hat circumference of around 50cm will stay put without feeling tight.
- Why: This is the key measurement for any close-fitting knit hat, including tuques, beanies, and snug caps. This measurement can also serve as a useful reference point when thinking about a sweater neckline circumference. Just keep in mind: neckline shaping (like crew neck or v-neck) will increase the opening, so this would also have to be taken into account.
Head Height
- Where: Measure from just below one earlobe, up and over the top of the head, to just below the opposite earlobe. Divide this number by two to get, for example, the height measurement of a knit hat.
- Why: This measurement helps determine how deep your tuque or hat should be to sit comfortably and cover the ears (or not, if you’re going for a shorter style). It’s especially handy when designing hats with folded brims, slouchy silhouettes, or fitted ear coverage.
🧵 Measuring for Gauge
Start with a swatch: Before you cast on the real thing, knit a swatch using the same yarn, needles, and stitch pattern you plan to use. A good size is at least 4″ × 4″ (10 cm × 10 cm), but a bit more with a garter stitch border works great so you have enough area to measure without edge distortion.
Let it relax: If your yarn may change dramatically after blocking, treat your swatch the same way you’ll treat your finished item. Measuring after blocking your swatch helps your measurements reflect how the fabric will behave in real life.
Check your gauge: Use a ruler or gauge tool to count how many stitches and rows you have per 4 inches (10 cm). Be sure to measure in the centre of the swatch to avoid edge curl or tension shifts.
Don’t stop there: Gauge can shift as you knit! Check again partway through your project:
- If your tension changes, you can either adjust how you knit (or change your needle size), or
- Recalculate your measurements using your current gauge (especially if using a calculator like this one)
A little checking at the beginning saves a lot of frogging later.
📎 Extra Tips for Measuring
- ✏️ Remember to allow for ease—For sweaters, aim for at least 2-4″ (5-10cm) of positive ease for comfort and layering, unless making a form-fitting sweater, which may benefit from a bit of negative ease for a sleeker silhouette. . For close-fitting items like tuques, mitts, and socks, use 10–15% negative ease (i.e. the finished item should be 85–90% of the body measurement) for a snug, secure fit.
- 📋 Keep your notes! They’ll come in handy if you knit for others or revisit the calculator later