Here's what UKBA say:-
Income £ Leave to enter/remain:
Savings requiredFurther leave to remain:
Savings requiredIndefinite leave to remain:
Savings requiredNo income £62,500
(16k+ (18,600 x 2.5))£62,500
(16k+ (18,600 x 2.5))£34,600
(16k+ 18,600)Income of £15,000 £25,000
(16k+ (3,600 x 2.5))£25,000
(16k+ (3,600 x 2.5))£19,600
(16k+ 3,600)Income of £18,000 £17,500
(16k+ (600 x 2.5))£17,500
(16k+ (600 x 2.5))£16,600
(16k+ 600)
Just food for thought
Hope it helps