How many carriers are needed to keep three available?

What would a law requiring the Royal Navy to operate three carriers at once imply for fleet size?

The Navy would need at least six or seven carriers to sustain three available, with nine offering a more robust three-to-one cycle.

Deployed availability cannot be equated with total hull count because carriers rotate through maintenance, training, and readiness states. Six or seven could produce two at sea and another ready alongside, although that would be a tightly managed minimum. Nine would provide a cleaner three-to-one ratio, while ten might allow four available. Any such requirement would also demand a much larger air, escort, personnel, maintenance, and logistics establishment around the carriers themselves.