You have a maximum cost-per-click (max. CPC) bid of £2 for a keyword. To determine the prospective impact of raising this bid to £3, you could use:
Explanation: The regular Bid Simulators show you how changes to your max. CPC bid might change the cost or the number of clicks, impressions, conversions, and conversion value your ads would have received for your keyword or ad group. You can find them on the Ad groups and Keywords tabs.
Read more here: https://support.google.com/adwords/answer/2470105?hl=en
you have a maximum cost-per-click bid of us$2