Your capital is considered a part of your wealth. Excluding any items of personal use, you have an obligation to pay 2.5% zakat on your wealth once a year. If your capital is contractually locked in for a period of time then it can also be excluded from your zakat for that period.
In addition to wealth, there is also zakat on production. In your case where you have invested your capital but are not materially involved in the business, you are obligated to pay 10% zakat on your gross profits every time you receive your profits. For ease in calculation, you can defer this zakat and pay it on a schedule, for example, once a month or once a year.
You may enter appropriate numbers in our Zakat Calculator after reading the description for each box. When you reach the end, it will generate a statement showing you exactly what you owe after any applicable deductions, and what percentage was applied to each category. It is also a great way to learn the sharia of zakat.
View Zakat Calculator