Climb rates at and times to altitudes for the Mercury-powered G.1A are as follows (times are total from 0 m)-
at 4,500 kg gross weight
at sea level (0 m) : 13.9 m/sec.
at/to 1000 m : 13.9 m/sec, 1 min 10 sec.
at/to 2000 m : 13.9 m/sec, 2 min 25 sec.
at/to 3000 m : 13.9 m/sec, 3 min 35 sec.
at/to 3200 m : 13.9 m/sec.
at/to 4000 m : 12.2 m/sec, 4 min 50 sec.
at/to 5000 m : 10.1 m/sec, 6 min 20 sec.
at/to 6000 m : 8.1 m/sec, 8 min 10 sec.
at/to 7000 m : 6.1 m/sec, 10 min 35 sec.
at/to 8000 m : 4.1 m/sec, 13 min 50 sec.
at/to 9000 m : 2.2 m/sec, 19 min 5 sec.
at 5000 kg gross weight:
at sea level (0 m) : 13.3 m/sec.
at/to 1000 m : 13.3 m/sec, 1 min 15 sec.
at/to 2000 m : 13.3 m/sec, 2 min 35 sec.
at/to 3000 m : 13.3 m/sec, 3 min 50 sec.
at 3250 m : 13.3 m/sec.
at/to 4000 m : 11.6 m/sec, 5 min 10 sec.
at/to 5000 m : 9.6 m/sec, 6 min 45 sec.
at/to 6000 m : 7.6 m/sec, 8 min 40 sec.
at/to 7000 m : 5.7 m/sec, 11 min 10 sec.
at/to 8000 m : 3.8 m/sec, 14 min 50 sec.
at/to 9000 m : 1.9 m/sec, 20 min 50 sec.