Total Time = Pace per 100m × (Distance / 100). Speed = 3.6 / Pace.
Why It Matters
You want to swim 1,500 meters at 2:00 per 100m (solid recreational pace). Your total time is 50:00 — perfect for a 1-hour workout with 10 minutes warmup/cooldown. At 1:45/100m (advanced), you finish in 42:30.