Scuba Weight Calculator

As scuba instructors, the question we are asked most often by new and experienced divers is “how much weight do you think I need?” We then use the following to guesstimate how much weight a diver will need; their body type, body fat to muscle ratio, what exposure protection they are wearing, and how much diving experience they have. We have personally seen so many divers that we are quite accurate with our estimates, so we have developed a scuba weight calculator for you to try out!

With our scuba weight calculator, we hope to provide you with an estimate of how much weight you need on your dive. So this means on your next dive trip when the divemaster asks you, “how much weight do you need?” you can answer with a ballpark figure!

Skip to the Dive Weight Calculator | Skip to the User Manual

Buoyancy Check

Before diving in a new area with new equipment you should always do a buoyancy check on the surface. The buoyancy check is easy to complete.

Here are the steps:

  1. Enter the water with all your equipment on
  2. Make sure your mask is on and your regulator is in
  3. Completely deflate your BCD while holding a normal breath
  4. Without swimming, you should float at eye level

When you exhale you can expect to sink down.

That is how you know that you are properly weighted for diving.

Getting Started

Our scuba diving calculator will give you a scuba weight rule of thumb that you can work from. We recommend using these results when you conduct your buoyancy check.

The formula is a combination of the PADI basic weighting guidelines, user feedback, and our combined dive instructing experience.


There are a large portion of outliers when it comes to scuba weight calculation. It is impossible to adjust for these in a script. This is why we can’t guarantee that it will work for everyone. For most people it should however be fairly accurate.

Time to get stuck in!

SCUBA Weight Calculator

Scuba Weight Calculator

Metric Imperial
Salt Fresh
Aluminium Steel

© Down to Scuba

User Manual

Welcome to the official Down to Scuba Weight Calculator user manual. We designed the calculator for ease of use and it should be self-explanatory for the most part. You can find more information on it below.


You can choose whether you want to conduct your calculation using metric or imperial units. The calculator defaults to using metric units, so by default, the result of the diving weight calculator will be shown in kg.

To switch units, simply select the desired radio button at the top of the calculator.

Personal Data

You can enter several pieces of personal data, namely your weight, your height, and your scuba diving experience level.

Weight & Height

Simply enter your weight and height in the requested units as accurately as you can.

The height parameter is optional. If you leave it blank, the calculator will assume a normal BMI. If you add your height, the calculation will slightly adjust to underweight and overweight BMI metrics.

Experience Level

The calculator will assume you are a beginner if you do not select any experience level. The different experience levels are designed as follows:

Beginner: Someone that is learning to dive and has less than 10 dives.

Advanced: This is someone that dives regularly and has 30+ dives under their belt. They have experience in various different diving environments.

Expert: An expert diver is someone that has dived for several years regularly and has 50+ dives. They are experienced in various environments and are comfortable diving without a guide.

What about professional level divers? Well, we really appreciate you testing our calculator as a dive pro. The category was not included as dive professionals can dive with extra weight (for their customers) and almost no weight (when they didn’t bring enough down), also dive pros shouldn’t have to use a calculator.

Environmental Data

The calculation also takes into account the environment in which you plan to dive in. You can choose between saltwater and freshwater. The calculator defaults to saltwater.

You should need slightly less weight in freshwater given that you wear the same exposure suit. There are different salinity levels in the world’s oceans and your local dive pros will further adjust for that.


It really matters what type of exposure protection you are wearing on your dive as well as what material your scuba cylinder is made of.

Exposure Protection

Thicker neoprene requires more weight. A drysuit generally requires more weights. Here are the classifications of each exposure suit option:

Swimsuit: No neoprene. A rash guard or simple board shorts of a bikini.

3mm Wetsuit: A 3mm short arms, short legs wetsuit. Common in tropical waters.

5mm Wetsuit: A full length 5mm wetsuit.

7mm Wetsuit: A full length 7mm wetsuit. If you are wearing a second jacket, you would need to adjust for this.

Drysuit: A shell drysuit with normal undergarments.

For most people if you wear a 5mm jacket, using the 3mm wetsuit option gives you a fairly accurate result.

Scuba Tank Material

The material of the tank affects the amount of weight needed by the diver. Diving with a steel tank requires less weight than diving with an aluminium tank. The calculator allows you to specify aluminium or steel tanks.

The calculator defaults to aluminium tanks.


The calculated weight result will be displayed in either kg or lbs. You can choose your units at the top. The result is rounded to 2 decimal places. Most of the time even the best scuba weights won’t allow for a 0.12kg adjustment, in this case, we recommend to go as close as you can.

Diving weights are most readily available in 1kg and 800g weight variations.

Embed the Scuba Weight Calculator

We are working on a way to make our calculator embeddable. The goal is to make it super easy to embed it on your own website or blog while maintaining our ability to continue improving it.

Check back here for instructions on how to embed our dive weight calculator.

The Perfectly Weighted Conclusion

From the feedback we received so far on our scuba weight calculator, we plan to continually improve its formula. As stated above, it won’t work for every individual as we are all completely unique and there is no algorithm for that.

We hope it continues to help divers around the world and we appreciate any feedback in the comments below.