Scuba Brief

Nitrox & Trimix

  • Nitrox CalculatorMaximum operating depth (MOD), best mix and equivalent air depth (EAD) for enriched air nitrox.
  • Nitrox Blending CalculatorHow much oxygen and air to add for a nitrox fill, from an empty cylinder or with gas already in it.
  • Trimix CalculatorOperating depth range, equivalent narcotic depth (END), best mix and partial-pressure blending for helium mixes.
  • CNS / OTU CalculatorCNS clock percentage and OTU (oxygen tolerance unit) accumulation based on oxygen partial pressure (ppO₂).

Decompression & Tables

  • DECO 2000 TableThe dive table used in CMAS training: no-deco limits, group letters and surface interval credits.
  • DECO 2000 PlannerEnter depth and time to get the dive profile, deco stops and group letter. Works for repetitive dives too.
  • Multi-Gas Deco PlannerDecompression stops for air, nitrox or trimix with up to two deco gases, from the Bühlmann ZHL-16C model with gradient factors.
  • Altitude Diving CalculatorAir pressure at a mountain lake, the sea-level equivalent depth to use with tables, and adjusted stop depths.

Gas Planning

  • SAC CalculatorWork out your surface air consumption (SAC) in L/min from the pressure, time and depth of a logged dive.
  • RMV CalculatorConvert a SAC rate in bar/min to RMV in L/min and back, so your breathing rate works with any cylinder size.
  • Gas PlanningGas required for a dive, minimum reserve (rock bottom) and turn pressure by the rule of thirds.
  • Tank Duration CalculatorHow many minutes your gas lasts at a given depth, from your SAC rate, tank size and the pressure you keep in reserve.

Weighting

  • Scuba Weight CalculatorA starting amount of lead from your body weight, exposure suit, tank and water type, to fine-tune with a buoyancy check.

Conversions

  • Dive Unit ConverterConvert bar and psi, metres and feet, kilograms and pounds, °C and °F, and cylinder sizes between litres and cubic feet.
Browse all tools

Gas & Nitrox

  • SAC Rate Basics
  • Tank Duration
  • Rock Bottom Gas
  • Is Nitrox Worth It?
  • MOD, EAD and Best Mix
  • CNS & OTU Tracking

Decompression & Time Limits

  • No-Decompression Limits
  • Safety Stops
  • Surface Intervals
  • Dive Computer Algorithms
  • Reading the DECO 2000 Table
  • Flying After Diving

Skills & Safety

  • Buddy Checks
  • Buoyancy & Trim
  • Weighting
  • Equalizing Your Ears
  • Nitrogen Narcosis
  • DCS Symptoms & First Aid

Gear & Travel

  • First Dive Computer
  • Choosing a BCD
  • Wetsuit Thickness
  • Where to Dive Each Month
  • Red Sea Diving
  • First Liveaboard
Browse by topicDive Computers & DecompressionDive DestinationsTraining & CertificationSafety & Dive MedicineScuba GearBrowse all guides
DECO 2000

Blog

Scuba diving guides

Articles on dive skills, certification, dive planning and dive sites.

Browse by topic

  • Dive Computers & Decompression
  • Dive Destinations
  • Training & Certification
  • Safety & Dive Medicine
  • Scuba Gear

Filter by tag

Training & Certification · June 22, 2026 · 9 min read

Scuba Diving vs Snorkeling: Is Scuba Harder, and Which Suits You?

Scuba diving vs snorkeling: training, depth, time underwater, cost and risk side by side, with try-dive rules from PADI and SSI and snorkel safety research.

Read more

Safety & Dive Medicine · June 20, 2026 · 8 min read

Is Scuba Diving Dangerous? Death Rates, Causes and Who Is at Risk

Scuba diving death rates from DAN reports and peer-reviewed studies, what causes fatal accidents, who is most at risk and the steps that lower it.

Read more

June 18, 2026 · 4 min read

How Was Scuba Diving Born? Who Was Jacques Cousteau?

How Was Scuba Diving Born? Who Was Jacques Cousteau? Meta description (150-160): The birth of scuba diving: from the 1943 Aqua-Lung to CMAS, the life of Jacques Cousteau and a short history of recreational diving.

Read more
←123456

Planning a dive?

Check your nitrox depth, gas reserve and no-deco time before you get in the water.

Open the calculatorsRead the guides
Scuba Brief

Free dive calculators and scuba guides for recreational and technical divers.

Dive tables

  • DECO 2000 Table
  • DECO 2000 Planner

Calculators

  • Nitrox Calculator
  • Nitrox Blending Calculator
  • Trimix Calculator
  • CNS / OTU Calculator
  • SAC Calculator
  • RMV Calculator
  • Gas Planning
  • Tank Duration Calculator
  • Multi-Gas Deco Planner
  • Altitude Diving Calculator
  • Scuba Weight Calculator
  • Dive Unit Converter

Guides

  • Dive Computers & Decompression
  • Dive Destinations
  • Training & Certification
  • Safety & Dive Medicine
  • Scuba Gear

Site

  • All tools
  • Blog
  • About
  • Editorial policy
  • Contact
  • Privacy Policy
  • Terms of Use

© 2026 Scuba Brief. All rights reserved.

These calculators don't replace dive training or a dive computer.