How to Measure

Your results are only as accurate as your measurement. Two numbers go into the calculator: erect length (bone-pressed) and erect girth. Measure the same way every single time, and the numbers will mean something.

Before you start

• Get fully erect. Erection firmness changes the reading. A soft erection measures short. Measure at your firmest, and use that same firmness every time.
• Use the right tools. A rigid ruler for length (a soft tape bows along the shaft and reads long) and a flexible tape measure for girth. No flexible measuring tape? Wrap a strip of paper or a length of string, mark where it meets, then lay it flat against the ruler.
• Pick your unit and stick to it. Choose inches or centimeters in the calculator and measure in that same unit throughout. Never mix the two.
• Stay consistent. Same posture, same room temperature, and the same time of day if you are tracking change over time. Standing is recommended because it makes posture easier to repeat.

Step 1 · Erect Length (Bone-Pressed)

Why bone-pressed? Pressing past the fat pad to the bone means you measure the same anatomy every time, instead of however much soft tissue happens to be in the way that day. It is what makes the number repeatable.

1. Get fully erect. You may gently position your penis so it sits parallel to the floor, but do not pull, stretch, or extend it forward. Any tension inflates the result.
2. Lay the ruler along the top center of the shaft, running straight down the midline, with the starting edge at the base.
3. Check where the scale begins. The ruler's measurement scale must start at the physical edge. If there is a gap before the zero mark, either line the zero mark up with the base or subtract that gap from your reading. Do not count empty space as length.
4. Press the end in through the fat pad until it stops firmly against your pubic bone. Steady, even pressure.
5. Read the mark at the very tip of the head. Nothing past the tip counts.

→ That number is your Bone-Pressed Erect Length (BPEL). Type it into the Length box.

Measuring without pressing to the bone (the ruler resting on the fat pad) gives Non-Bone-Pressed (NBP) length, which reads shorter. Use the BP / NBP toggle to match how you measured.

Step 2 · Erect Girth

1. Stay fully erect.
2. Wrap the flexible measuring tape around the mid-shaft, halfway between the base and the head. This single mid-shaft measurement is what the calculator's comparison data is based on, so it is the location to use.
3. Keep the loop straight, level, and perpendicular to the shaft. The tape should form a flat circle at a right angle to the length, not sitting at a diagonal, which reads too large.
4. Snug, not tight. The tape should sit flat against the skin without denting it.

→ That measurement is your Erect Girth (EG). Type it into the Girth box.

Dialing it in

• Keep the ruler straight along the top center. Do not follow an upward curve.

This method is standard across the scientific community and PE community alike.