Scuba Diving Calculators
Free scuba diving calculators: tank air duration, weight belt requirements, surface interval limits, no-decompression dive times, and more.
Nitrox MOD and ppO2 Calculator
Calculate maximum operating depth and oxygen partial pressure for any nitrox mix. Find MOD for both working and absolute ppO2 limits.
Equivalent Air Depth (EAD) Calculator
Calculate the equivalent air depth for any nitrox blend (EAN32, EAN36, custom mix) at a given depth. Plan dives using standard air decompression tables.
Scuba Gas Volume at Depth Calculator (Boyle Law)
Calculate compressed gas volume at depth using Boyle Law. Enter surface volume and depth to see how much your air shrinks at 30, 60, or 100 feet underwater.
Scuba SAC Rate from Dive Log Calculator
Calculate Surface Air Consumption rate from a real dive log. Enter tank pressure used, depth, and time to get your personal SAC for gas planning.
Scuba Diving Weight Calculator
Estimate the amount of lead weight needed for scuba diving based on body weight, wetsuit thickness, water type, and tank material.
No-Decompression Limit (NDL) Calculator
Look up no-decompression limits (NDL) by depth from PADI recreational dive tables. Maximum bottom time before a decompression stop is required.
Repetitive Dive Interval Calculator
Estimate the surface interval needed before a repetitive scuba dive. Uses a simplified residual nitrogen model based on your first dive depth and time.
Scuba Surface Interval Calculator
Calculate how your pressure group changes during a surface interval between dives. Based on PADI dive tables for repetitive dive planning.
Scuba Tank Duration Calculator
Calculate how long a scuba tank will last at a given depth. Enter tank size, pressure, and your surface air consumption (SAC) rate.
Scuba Weight Belt Calculator
Estimate how much weight to wear for scuba diving. Based on your wetsuit thickness, body composition, tank type, and water salinity.
Surface Air Consumption (SAC) Rate Calculator
Calculate your Surface Air Consumption (SAC) rate from a dive log entry. Use your SAC rate to predict tank duration for future dives.