Net your trading assets — inventory, receivables and cash — against payables and short-term liabilities, then compare to the Nisab.
Use the Nisab Calculator to work out the current Nisab in your currency, then enter it above.
This is a simplified "current assets minus current liabilities" method for trading businesses, based on assets held for one full lunar year. Fixed assets like shop fittings, vehicles and buildings used in the business (not for resale) are generally excluded. Complex partnerships and mixed-use assets can differ — please confirm with a qualified local scholar or accountant familiar with Zakat.