Future Wrist · Dive Tools

The Diver's
Calculator Suite

Eight precision tools for planning, executing, and recovering between dives — built around the same principles as a well-engineered dive watch.

8Calculators
2Unit Systems
0Sign-ups Required
01
Air Consumption
Surface Air Consumption (SAC) Rate
Your SAC Rate
—cu ft/min
Enter values and calculate
Depth Pressure— ATA
Air Consumed—
Surface Equivalent—
What's a good SAC rate?
  • Excellent: under 0.5 cu ft/min (14 L/min)
  • Average: 0.6–0.8 cu ft/min (17–23 L/min)
  • High: over 0.9 cu ft/min — try slowing your breathing
02
Decompression Planning
No-Decompression Limit (NDL) Lookup
Based on PADI recreational dive tables for a single no-decompression dive at sea level. Personal dive computer always takes priority over a generic table.
No-Deco Limit at this Depth
Within Limits
—min
Maximum allowed bottom time
Planned Time— min
Time Remaining—
Pressure Group—
03
Physics of Depth
Water Pressure at Depth
The 10m / 33ft rule: Pressure increases by approximately 1 atmosphere for every 10 meters (33 feet) of saltwater depth. At 30m, your body experiences 4× surface pressure.
Absolute Pressure at Depth
—ATA
Compared to surface (1 ATA)
Gauge Pressure— PSI
In BAR— BAR
Air Density Multiplier— ×
Compared to Surface— ×
04
Safe Ascent
Ascent Rate Monitor
Safe ascent rate: 30 ft/min (9 m/min) or slower. Ascending too quickly can cause decompression sickness and lung overexpansion injuries.
Your Ascent Rate
Safe
—ft/min
Within recommended limits
SLOW 30 FT/MIN DANGER
05
Nitrox Diving
Maximum Operating Depth (MOD)
Common Nitrox blends: EAN32 (32% O₂) and EAN36 (36% O₂). Going below your MOD risks oxygen toxicity, which can cause underwater seizures.
Maximum Safe Depth
—ft
— meters
Gas BlendEAN—
Nitrogen %—
Equivalent Air Depth— ft
06
Live Timer
Safety Stop Timer (3 min @ 15 ft)
Why this matters: A 3-minute stop at 15 ft after every dive allows dissolved nitrogen to off-gas, dramatically reducing the risk of decompression sickness. It's the most common real-world use of a dive watch bezel.
Test it in your browser before the dive — then trust your bezel underwater. A good unidirectional bezel does the same job, mechanically, without batteries.
Safety Stop Countdown
03:00
Ready to start
07
Between Dives
Surface Interval Tracker
Why surface intervals matter: Your body needs time to off-gas residual nitrogen between dives. Most agencies recommend a minimum 1-hour interval; longer is safer, especially before any deeper or repetitive dive.
Your Surface Interval
Calculate to check
—min
—
Minimum Recommended60 min
Safe for Repetitive Dive—
08
Quick Reference
Universal Dive Unit Converter
Depth
⇄
Pressure
⇄
Temperature
⇄
Educational use only. These calculators are reference tools, not a substitute for proper dive training, current dive tables, or a personal dive computer. Always plan dives within your certification level and listen to your dive computer first.
The Future Wrist Collection

Tools you can trust on land.
A watch you can trust below.

Mechanical reliability. Unidirectional bezels. Built around the same principles as these calculators — precision, safety, and zero compromise.

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