If your ankles have started puffing up by mid-afternoon, or your legs feel heavy after a short walk, you are running into one of the most common physical shifts of pregnancy.
Your blood volume increases through pregnancy, hormonal changes affect your blood vessels, and your growing uterus adds pressure in the pelvis. Pregnancy, Birth and Baby explains that swelling in the ankles, feet and fingers is a normal part of pregnancy, usually worse at the end of the day and better again by morning. Healthdirect has more on fluid retention generally.
Graduated compression socks are one of the simplest, drug-free things many women reach for. Pregnancy Birth and Baby lists compression stockings among the practical measures that can help with varicose veins, alongside resting with your legs up.
But none of that helps if the fit is wrong. Here is how to measure properly, pick the right size, and end up with socks you can actually wear all day.
If you are dealing with leg heaviness alongside pelvic pressure or pain, it is worth getting proper guidance rather than sorting it out from a size chart alone. Pelvic Wellness Physio shares practical, pregnancy-safe advice on managing that kind of daily load.

Why the Fit Matters So Much
Compression socks do not work like regular socks. Instead of applying even pressure everywhere, maternity compression socks use a graduated profile: firmest at the ankle, easing gradually as it moves up your calf.
Get the size wrong and you run into one of two problems:
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Too large: the sock feels loose, wrinkles around the ankle, and doesn't deliver the graduated profile it was designed around. You end up wearing them without much benefit.
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Too small: the top band digs into your calf or behind your knee. Rather than a smooth gradient, you get a tight band partway up the leg, which is uncomfortable and can leave red marks.
A well-fitted pair should feel like a firm, supportive hug around your lower leg. Snug, but comfortable enough that you forget about them by mid-morning.
The Best Time of Day to Measure
Timing genuinely matters here, and it is the step most people skip.
The rule is simple: measure first thing in the morning, right after you get up.
Overnight, lying flat, fluid that has collected in your lower legs redistributes, so your ankles and calves are at their slimmest when you wake. If you measure at 4pm instead, you are measuring a leg that has already swollen through a day of sitting or standing. Size from those numbers and you will end up with socks that are too big for your actual frame, which means they won't fit properly on the mornings you put them on early.
Step-by-Step: How to Measure at Home
Grab a soft fabric measuring tape (the flexible sewing kind, not a builder's tape) and something to write your numbers down in centimetres.

1. Measure Your Ankle
Sit on the edge of your bed with your foot flat on the floor. Wrap the tape around the narrowest part of your ankle, just above the ankle bone. Keep it flat against your skin, neither pulled tight nor left slack. Write the number down.
2. Measure Your Calf
Move up to the widest part of your calf muscle. Wrap the tape around, making sure it sits straight across rather than on an angle. Write that number down too.
3. Note Your Shoe Size
Your ankle and calf measurements do the real work, but your Australian shoe size helps make sure the footbed and toe area sit comfortably without bunching inside your shoes.
Matching Your Measurements to the Size Chart
With your three numbers, compare them against the size chart for the socks you are buying.
For maternity compression, prioritise your calf and ankle measurements over your shoe size. The graduated profile depends on the sock sitting correctly around your leg, so a pair that fits your calf properly will feel right even if your shoe size sits on the boundary between two options.
If You Sit Between Two Sizes
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Size up if: you are early in your second trimester and expect a bit more swelling as things progress, or you prefer a softer, easier-to-pull-on feel.
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Size down if: your measurements are only just into the larger bracket and you like a firmer, more supportive snugness.
What to Look For in a Maternity Compression Sock
Once you have your size sorted, a few features make the difference between socks you wear daily and socks that live in a drawer:
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A verified compression rating: look for an ARTG-listed Class I product with a 15 to 25 mmHg graduated profile, which is the moderate range commonly recommended in pregnancy.
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Soft, breathable bamboo blend: bamboo feels gentle against sensitive skin, breathes well, and helps wick moisture so your feet don't overheat.
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Anti-slip soles: as your centre of gravity shifts, discreet grips on the sole give you extra stability on timber floors and tiles.
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Easy pull-on stretch: a flexible weave lets you get the sock over your foot and heel without straining, which matters more every week.
Sleepybelly Maternity Compression Socks tick each of those boxes: an ARTG-listed (ARTG 521641) 15 to 25 mmHg graduated design, soft bamboo fabric, and non-slip soles, in a weave that pulls on without a fight.
If you are still deciding on length before you measure, our guide on thigh-high vs knee-high compression socks covers which suits most pregnancies.
How to Put Them On With a Bump in the Way
Pulling on a snug sock at 32 weeks can feel like a workout. The "turn inside out" method makes it much easier:
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Reach inside the sock and grab the heel pocket from the inside.
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Turn the top portion inside out, leaving just the toe and heel pocket right-side in.
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Slide your foot in until your heel sits properly in the heel pocket.
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Gently unroll the rest of the sock up over your ankle and calf.
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Smooth out any wrinkles with your palms. Never roll the top cuff down, since that creates exactly the tight band you are trying to avoid.

Once the Socks Come Off
Compression handles your active daytime hours. Your evening is for letting everything settle:
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Put your feet up: rest your feet on a couple of pillows so they sit slightly above heart level while you are on the couch.
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Soothe tired muscles: many women find massaging Sleepybelly Magnesium Body Cream into their calves a calming pre-bed ritual.
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Support your hips overnight: side-sleeping with a cushion like the Sleepybelly Pregnancy Pillow between your knees and ankles keeps your legs parallel and takes pressure off your lower back.
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Wear something forgiving: breathable pyjamas with an expandable waistband, like the Sleepybelly 3-Piece Maternity Pyjamas, so nothing digs in while you rest.
Once you have the fit right, the next question is usually how many hours a day to wear them. Our guide on how long to wear compression socks each day walks through building a daily routine around your work and activity.
The Bottom Line
Getting the right size comes down to one habit: measure your ankle and calf first thing in the morning, before the day's swelling sets in. Size from your true measurements rather than your afternoon ones, prioritise calf and ankle over shoe size, and you will end up with a pair that feels supportive rather than restrictive right through your pregnancy.
Frequently Asked Questions
Should I size up as my pregnancy progresses?
Usually not. A morning measurement taken early in pregnancy reflects your actual leg structure, and quality maternity socks have enough built-in stretch to handle normal daily fluid changes while keeping their graduated profile. If your measurements change substantially, re-measure rather than guessing.
How high up my leg should knee-high socks sit?
About two finger-widths below the bend of your knee. They should never fold over or be pulled up over the kneecap, since that creates pressure right where you don't want it.
What if my socks leave light marks on my skin?
Faint impressions from the fabric weave or the top cuff are normal, much like the mark a bra strap or waistband leaves. But if you get painful indentations, redness, numbness or tingling, the size is likely too small and it is worth going up a size or checking in with your midwife or GP.
The information in this article is general in nature and intended as comfort support only. It is not medical advice. Always consult your midwife, GP, or a qualified healthcare provider for guidance specific to your situation.