So you know you need to wear weights for scuba diving otherwise you wouldn’t be able to do it down.

But if you’re wearing too much weight then achieving neutral buoyancy becomes challenging.

And you’ll end up wasting a ton of your precious air to maintain it.

Not to mention the additional effort required to drag around that all that unnecessary weight.

So the question is how much weight do you need for scuba diving?

While the answer is different for every diver, the goal is exactly the same. You want to have just enough weight to dive safely and efficiently but not an ounce more.

And that’s why we’ve created this calculator to help you figure out the amount of weight you need for diving.

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ScubaOtter Diving Weight Calculator

About You:


Your Equipment:


Your Environment:


How to Use the ScubaOtter Weight Calculator

All you need to do is input your weight, in either lbs or kgs, and a little bit about yourself, your equipment, and the type of water you’ll be diving in.

Press calculate and viola!

Our weight calculator will tell you how much weight you need to wear when you go diving with that setup.

But before you head off diving, it’s important to note that a weight calculator is just an estimate of how many weights you will need.

It’s a great starting point. But a weight calculator will never be able to give you the precise amount of weight you need for scuba diving.

So we highly recommend that you conduct a buoyancy check when trying the results from our weight calculator. From there you can easily add or subtract to find the optimal amount of weight you need for your dive.

There are several other factors that will affect the amount of weight you need for diving that weight calculators don’t take into account.

For example, if you’re wearing a brand new wetsuit you’ll need more weight than if you’re wearing an identical wetsuit has been used for over a thousand dives.

Similarly, the weight and buoyancy of your BCD, fins, and other accessories such as a dive knife, flashlight, or underwater camera, will also impact how much weight you need for diving.

And that’s why you’ve always got to test out the results you get from a weight calculator.

Why is Proper Weighting when scuba diving Important?

Being properly weighted is essential if you want to dive safely and efficiently.

Of course, you already know that if you don’t wear enough weight you won’t be able to get down at the start of the dive. Or you’ll struggle to stay down at the end when your tank is nearing empty.

Not only is floating up all the time frustrating, but it can also be dangerous.

If you’re not able to complete your safety, or emergency decompression stops, or ascend too fast then you’re at much greater risk of decompression illness. Not to mention the risks of popping up without an SMB inflated.

Now you might be thinking…

“I’ll just make sure I am overweighted so I can get down and stay safe.”

But it’s really not ideal to be diving overweighted either.

When you’re overweighted you’ll have to add a lot more air to your BCD to find your neutral buoyancy. Which means you’ll burn through your air much quicker and end up with shorter dives.

And even if you have the best air consumption in the world, you’re making your dive harder than it needs to be. Carrying that additional weight increases your drag in the water, further increasing your air consumption, and adding to post-dive fatigue.

Trust us, this is not something you want if you’re trying to make the most of 4 dives a day on a liveaboard. Or have to kick against a strong current!

Proper weighting when diving is the foundation of good buoyancy control. Wearing the right amount of weight when diving helps you to descend and ascend smoothly. It also allows you to easily maintain your position during your safety stop.

And with the correct weighting your overall positioning in the water, aka your trim, will be optimized making you as streamlined as possible.

As a result of all of this, you will be able to move much more efficiently underwater. Which leads to improved air consumption and longer, more comfortable dives!

Who doesn’t want that?!

How do I know if I’m properly weighted for scuba diving?

Weight calculator : How do i know if i'm properly weighted for diving?If you’re properly weighted for diving, you should be able to comfortably hover at your safety stop (between 10 and 20 ft or 4 to 6m) at the end of the dive with little to no air in your BCD, your tank near empty (around 700-900 PSI or 50-60bar), without exerting any effort to stay down and without popping up to the surface.

So now you’re probably wondering, ‘how do I make sure I am properly weighted before I go diving?’

Well, you can start by getting an estimate using our weight calculator above. Then you can conduct a weight check, also known as a buoyancy check, at the surface before you go diving.

But remember, proper weighting is determined through a process of trial and error. So don’t be surprised if you don’t get your weighting quite right on the first try!

How to conduct a weight check

You can complete a buoyancy check at the surface by following these steps:

  1. Full gear up with your estimated weight and enter the water to where it’s too deep to stand.
  2. With your mask on and the regulator in your mouth, take a normal breath and hold it.
  3. Hang vertically in the water and fully deflate your BCD whilst holding that breath.
  4. If you are correctly weighted you should float at around eye level. As a test, you should slowly sink as you exhale.
  5. If you’re already sinking whilst holding the breath you’re overweighted. If you’re unable to sink down to eye level then you’re underweighted.
  6. Add or subtract weight until you can float vertically at the surface at eye level.

Keep your legs and arms as still as possible. If you kick or tread water this will push you upward and you won’t be able to determine the correct amount of weight you need.

How to conduct a weight check for divingBut remember you want to be slightly overweighted at the beginning of your dive to compensate for the buoyancy shift of your tank during the dive.

No matter what material your tank is made of, as you use up the compressed gas inside, the tank will get lighter.  And therefore it will become more buoyant towards the end of the dive.

So it’s also worth repeating this weight check at the end of the dive to give a more accurate reading of the amount of weight you need.


So now you know why it’s so important to be properly weighted for diving and how to figure out the amount of weight you need.

Have you tried out our weight calculator? Did it give an accurate reading for you?

Let us know your experience in the comments. We’re always looking to improve our calculations so we’d love your feedback!

Alexa Worswick Administrator

Alexa Worswick is a PADI + SSI scuba instructor, experienced freediver, and travel writer. With over 15 years of scuba diving experience in many locations across 3 different continents, she’s now based in Indonesia.

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Hi Alexa
Really enjoyed your article and the handy calculator is great.
Can I please pose a question.
If the only thing that changes between the beginning and end of a dive (at the safety stop) is that the diver has released about 3kg of air from the cylinder, then at the beginning of the dive, the diver needs to be neutral with at least 3kg of additional lead to compensate for the consumed air. So the total amount of lead is 3kg plus whatever is required to remain neutral at 5m with 50 bar of air in the tank.
Have I got this wrong?
Many websites describe neutral buoyancy checking at the end of the dive but do not mention compensating for the lost air when determine the lead to carry.

Alexa Worswick

Hi Duncan,

Thank you for your comment, I’m really pleased you enjoyed the article and found the calculator useful.

That is a great question! So you’re correct in thinking that a diver will become 2.5-3kg (approx. 6lbs) lighter from that start to the end of the dive (based on them finished with 50bar in their cylinder). However, you don’t need to add an additional 3kg on top. This method at the end of the dive already compensates for the air lost. That’s why we all recommend doing the check at the end of the dive.

If you can hover comfortably at 5m with 50bar with almost no air in your BCD, then you are already wearing the correct amount of lead. If you added another 3kg on top, you’d be significantly overweighted.

If you did this same check at the start of the dive with a full cylinder (200bar) and can hover at 5m with NO air in your BCD then you are underweighted as this does not compensate for the air consumed during the dive. That is when you would consider adding 2.5 – 3kg to take into account the air lost during the dive. However, doing a check like this at the start of a dive is not really recommended because you’re using air that you could save for your dive and it doesn’t compensate for the air used. It’s much easier and more efficient to check your weight at the safety stop when you have at least 3 minutes to kill and this takes into account the air lost during the dive.

But if you do want to check your weight before a dive, it’s much better to use the surface weight check method I chat through above (hold a normal breath and fully deflate your BCD, you should float around eye level holding the breath and as a double-check, you should sink slowly as you exhale). Although you’ll always be slightly overweighted at the start of a dive to compensate for the air lost during the dive so it’s much more accurate to check at the end.

Ideally, you want to do both a surface check at the start, and then also check at your safety stop so you can really fine-tune to find the correct amount of lead to wear.

I really hope that helps answer your question, and if not then please let me know!




This calculator has been really helpful and close for what I had been using, the best part is that I am trying a different place and gear so it could be really close of what I need, just remove 3 lb from the pony bottle or have it in mind !!!

Alexa Worswick

Hey Carolina, thank you for your comment! Really pleased that the calculator works well for you, please do let us know how you get on with the new location and gear. Happy bubbles!

Mike Welch

Your calculator is the first one to “guess my weight”. Unfortunately, network isn’t always available. You all should make this as an app. Please?

Alexa Worswick

Hi Mike,

Thanks for your comment – super happy to hear it’s the first calculator that’s guessed your weight! I’ve previously been frustrated by these calculators so spent some time playing around with how we could make ours more accurate. We love the idea of making this into an app – appreciate that network isn’t always available when traveling & diving. Maybe a new focus for ScubaOtter in 2021!

If you have any ideas for the app – let us know!


Arnie Wilenken

Tried this calculator before a local dive. Needed a reasonable weight “hack” for a shorty suit I hadn’t worn in quite awhile. The gear selection options with this application are notably greater than with other like calculators. Quick and very user-friendly! Excellent piece of software! Am saving this for future use and highly recommend!!!

Alexa Worswick

Hi Arnie,

Thank you so much for your comment – it’s really helpful to have feedback from other divers trying it out and I am happy to hear it worked well for you. Did you find the calculator was a good guess for you? Or was it slightly above or below? Would be great to know what you inputted and how accurate it was for you so we can collate feedback and tweak it as needed.

As I’ve mentioned in other comments, many calculators don’t take into account the wide variety of factors that affect the amount of weight you needed. So I wanted to try to create something that addressed at least some of those based on my experience instructing.


Nice! Thank you. I have made a grid chart, various exposure suits down the left, two top columns FRESH, SALT. Within each box I have Front weight pockets + Back weight pockets (trim) = total weight. This is simple, but just never thought of it- a dive instructor showed me a chart like this. Maybe this will help someone.

I put your results in each box as a starting point- really accurate. I then update the numbers when in the water. Really accurate starting points. I am sort of an older guy starting to dive so I won’t make a career of diving (as much as I LOVE IT), so I wish you the best of luck.

Alexa Worswick

Hi Brad,

Thank you for sharing your grid method! I’m sure that’s going to help someone, especially in those situations where we don’t have access to the internet. And I’m very pleased to hear that our calculator results aligned with this method too! I don’t believe you’re ever too old to make a career out of diving, there are so many different avenues you can go down if health allows of course. But it’s also great to keep diving just for fun!

Wish you all the best with your future diving adventures!


I think your calculator is off, might need to update an incorrect dataset. Your calculator says a 170 lbs that I need to fill my BCD with 90 lbs of weight. Calculations should be roughly 10% of body weight, your calculator shows 53% of my body weight.

Alexa Worswick

Hi Matt,

Thanks for your comment. Our calculator takes into account much more than just a person’s body weight, so for us to check the data set we need to know what else you inputted other than your weight. The calculator has been pretty accurate for most people when entering all of their data. Please let me know what you entered for each of the following: Gender, Body fat, Suit type, Water, Tank type, Experience level, from the drop-down menus?

Many thanks,

Nicholas Pace

Thank you. Very useful. But I think the calculator is slightly off as inputing 12l and 15l steel cylinders leads me to need less weight for the 12 than 15. This cannot be right since the 15l is about 3 5kg heavier than the 12l.

Alexa Worswick

Hi Nicholas,

Thanks for your comment – we appreciate the feedback on our article and the calculator. You’re correct that with a 12L steel tank our calculator should suggest slightly more weight than with a 15L tank if all other factors are the same. Let me look into our algorithims for the calculator and see what we can do to update that.

You’re correct that a 15L steel tank is around 3.5kg heavier than a 12L on land when full, and underwater the 15L is appriximately 1kg more negatively bouyant than the 12L when full. Which suggests that you would need slightly more weight when diving with a 15L steel tank vs a 25L.

When they are both empty (or almost empty towards the end of a dive) the 15l is only 0.25kg more negatively bouyant than the 12L due to the additional space inside and lower pressure of the air inside that space. Which means that you don’t want to add too much weight with the switch between cylinders or you’ll end up quite a bit overweight towards the end of the dive.

Thanks again for the feedback!


Thank you.
Your guidance is very useful for me.👍

Alexa Worswick

Hi Aemy,

Thank you for your comment – we’re happy you found the guidnace useful.