How to Measure Your Penis: A Practical Guide

Penis size is something a lot of guys think about - but far fewer know how to measure their equipment accurately.

Whether you’re doing it out of curiosity, to buy the right toy, to check condom fit, or to monitor changes over time, measuring your penis is a practical, useful skill. This guide will walk you through it clearly and confidently.

At a Glance

• Measuring your penis is about fit, comfort, and safety — not ego.
• All you need are simple tools: a ruler, soft tape, and consistency.
• Bone-pressed erect length (BPEL) is the gold standard for length.
• Girth matters most for condoms, toys, pumps, and cock rings.
• Track changes over time; consult a doctor if you notice sudden shifts.

Why Measuring Matters (Confidence, Fit, and Safety)

Accurate penis measurements aren’t about comparison or ego - they’re about practicality, comfort, and sometimes even health. Knowing your true size can help you:

• Choose the right condom to avoid slippage or discomfort
• Find sex toys that actually fit and feel good
• Size yourself for pumps or rings safely
• Track changes due to aging, weight fluctuation, medication, or injury
• Talk to a doctor about concerns with confidence and clarity

Ready to get started?

What You’ll Need

You really don't need any medical equipment or things you can't find in your house - just a few simple tools will do the job:

• A rigid ruler (for length)
• A soft measuring tape or string (for girth)
• A mirror (optional, but helps with accuracy)
• A notepad or phone to log results

Preparation Tips

When you've gathered the above, there are a few quick tips to keep in mind:

• You might want to trim or groom pubic hair if it interferes with measurement.
• Aim to measure in a warm, private space so temperature isn't holding you back.
• Try to get a full erection (or consistent stretch, for flaccid length).
• Do what you can to stay relaxed - tension can skew results.

How to Measure Length: The Standard, Research-Backed Method

The gold standard for measuring penis length is called the Bone-Pressed Erect Length (BPEL). It’s what researchers and doctors use to get consistent, comparable results. This is a way of measuring erect penis length - we'll move on to a flaccid penis length next.

Step-by-Step: Bone-Pressed Erect Length (BPEL)

1. Get fully erect.

2. Stand upright or recline with your back supported.

3. Place a rigid ruler on the top side of your penis (the measurements side facing you).

4. Press the ruler gently into the pubic bone - past the fat pad.

5. Measure to the tip of the glans (not the foreskin).

6. Record the number.

7. Repeat 2–3 times and average the results.

Alternative: Non–Bone-Pressed and Stretched-Flaccid

There are alternative ways to measure your actual penis length. The first is called the Non-Bone-Pressed Erection Length (NBPBL). The second is the Stretched Flaccid (SFPL) method.

Non-Bone-Pressed Erect Length (NBPEL)

The method here is largely the same as the BPEL method above - but this time, don’t press into the fat pad. This is an easier way of measuring penile length - but be warned, it's less consistent, especially if your weight fluctuates.

Stretched-Flaccid Length (SFL)

Since the two methods above require a fully erect penis, it's worth remembering there's an alternative - ideal if you can't get or maintain an erection for long enough to measure.

• While flaccid, gently stretch your penis straight out until you feel resistance. Rather than pulling the foreskin (if you have one) - it's better to grasp slightly behind the glans (penis head).
• Measure from the top, starting at the base to the tip.

Tip: Label your measurements clearly (e.g., "BPEL," "SFL") if you’re tracking over time.

How to Measure Girth (Circumference) Accurately

Now we've covered measuring the length of your penis, we can move on to girth (otherwise known as 'circumference'). This measurement is arguably even more important then length - especially when it comes to comfort with toys and condom sizing.

Step-by-Step: How to Measure Penis Girth

1. Use a soft flexible measuring tape or wrap a string around your erect shaft.

2. Measure at three points:

   • Base (near your body)

   • Mid-shaft

   • Just below the glans

3. Record all three and note which is the largest.

4. If using string, mark the overlap point, then lay it flat against a ruler.

Try to Avoid: Pulling the tape tight or letting it hang loose. Wrap snugly without compression.

Converting Girth to Width/Diameter (For Product Sizing)

If you're buying a cock ring or a pump, you'll often see sizes listed by diameter, not circumference. Diameter is the measurement across a circle, whereas circumference is the measurement around the circle.

Here's how to convert:

Formula: Diameter = Circumference ÷ 3.14

Example Table:

Getting Consistent Results: Conditions and Timing Matter

Although your penis might always look the same size at a glance, the size can change based on a range of factors. Changes in weight, hydration, stress, or medications can all impact size temporarily - making your penis either larger or smaller.

Because of this, it's a good idea to make sure the following conditions are the same each time you measure:

• Measure in a warm room (cold causes contraction).
• Use a similar arousal level each time.
• Measure standing or seated - but do it the same way every time.
• Stick to the same measuring tools.
• Average across 2–3 sessions for best results.

Common Mistakes to Avoid

Now, since people are often eager for their penis to be as large as possible, it's tempting to slightly mis-measure in an effort to get see larger numbers. That's fine if you're flexing with your buddies - but when it comes to condom size, sex toy size, or finding a cock-ring that fits well, it's a good idea to be as accurate as possible.

Here are some common mistakes people make when measuring their penis:

• Measuring from underneath (instead of the top)
• Including foreskin in length
• Forgetting to press to the bone for BPEL
• Pulling tape too tight when measuring girth
• Measuring while cold, anxious, or half-erect
• Rounding up instead of noting exact numbers

How Your Numbers Compare

Penis size varies a lot, and averages only tell part of the story. That said, the average BPEL is ~5.16–5.5 inches and the average erect girth is ~4.5–5 inches.

Are you worried about how you measure up? Don't be. Countless studies have looked at penis length compared to partner satisfaction - and size rarely relates to how much fun people have in the bedroom.

It's tempting to read that and think it's not true - but this is where porn has had a huge influence on men's expectations. While some partners will have preferences, the overwhelming majority of people would prefer a good lover rather than someone who is simply packing more size.

Using Your Measurements: Condoms, Pumps, Rings, and Toys

Now that you know your numbers, here’s how to use them:

1. Condom Fit Basics

Try this: Start with a standard if you’re unsure. If it slips or feels too tight, try up or down one size.

2. Penis Pump Sizing: The Subtle Differences To Understand

Penis pumps usually require both length and girth to choose the correct cylinder. Some include built-in rulers or guides. For full details, see our Penis Pump Sizes Guide (with some helpful calculator tools to find the right pump for you).

3. Cock Ring Sizing: How This Relates to Penis Size

Cock rings rely on shaft girth to determine fit. It should be snug but not restrictive. For detailed steps and conversion charts, check out our Cock Ring Size Guide.

4. Sex Toy Sizing: How to Get the Most from Your Toys

Sleeves, strokers, and milkers all feel different depending on your size. Reading product reviews from men with similar measurements (or a panel of testers of different sizes) can help you predict sensation and fit. Bigger isn’t always better - fit is everything.

Tracking Changes Over Time (What’s Normal vs Not)

So, what happens if you see changes in your measurements? Penis size can fluctuate slightly day to day - but what matters is the overall trend.

If you're concerned (or pleased) to be seeing changes and would like to track the numbers, it's a good idea to:

• Log the date, method (BPEL/NBPEL/SFL), and conditions.
• Use the same ruler and tape each time.
• Talk to your doctor if you see any sudden or consistent loss in length or girth.

Useful fact: Some advanced penis pumps have built-in measurement guides - which can be handy for tracking over time.

Curvature, Hourglass, and Peyronie’s Considerations

Penises come in a huge range of shapes and sizes - and that's perfectly normal. However, there are some slight differences to note if your penis has a distinct shape.

• Got a natural curvature? Totally normal. Measure along the curve using a soft tape.
• More of an hourglass shape? Note it and record where the shaft narrows.
• Any new or painful bends? That could be Peyronie’s disease. Pause any device use and see a urologist.

When to See a Doctor

If you’ve noticed sudden or ongoing changes in your penis - like a loss of length or girth, painful erections, or a curve that’s getting worse - it’s worth speaking with a doctor.

Erectile dysfunction that’s new or progressively worsening can also be a sign of an underlying issue. Other symptoms to pay attention to include numbness, discoloration, or any trauma after using devices like rings or pumps. These aren’t things to ignore or tough out.

A quick conversation with a healthcare provider can bring peace of mind or catch something early. Pro tip: bring along your log of measurements and the methods you used. That kind of detail makes it easier for your doctor to understand what’s going on and give you the best guidance.

How to Measure Your Penis: A Summary

Measuring your penis accurately isn’t about comparison — it’s about knowing your body and making informed choices for comfort, safety, and pleasure.

Using the bone-pressed erect length (BPEL) and taking girth measurements at multiple points gives you a clear picture of your size. Be consistent with your method, track changes over time, and don’t stress small day-to-day differences.

Whether you’re sizing for toys, checking condom fit, or monitoring changes for health reasons, solid measurements help. When in doubt or if you notice concerning changes, talk to a healthcare provider. Knowledge is power — and it’s all yours.