No-one knows how many warheads each country has. Unlike Russia and the US, they are not bound by any treaty obliging them to reveal the extent of their arsenals.
Estimates vary wildly.
But Paul Beaver of the defence experts, Janes, speculates that Pakistan could have as many as 150 and India, 200-250. The majority of these warheads would be designed for delivery by bombs, not missiles. But this is not a simple two-way race. China, estimated to have 300 to 600 nuclear warheads, is a prime factor driving India's weapons programmes. And the fact that Pakistan's weapons programme has had considerable Chinese assistance has only increased India's concerns.