A working capital ratio of 2:1 is generally where you'd like to be, however you should take into account the type of business you run and how variable your cash flow is when deciding on the right working capital ratio for you.
Your working capital usually comes from your business cash flow. If you have a new business, or if your business operates in a seasonal industry, you might need some help covering the day-to-day running costs. Cash flow finance or a business overdraft could help you cover your working capital requirements