Tested tool guide
Tested browser tools
Checked August 16, 2026
What DSO / DPO / DIO Calculator does, with a checked example
Enter a period's credit sales, cost of goods sold, and average accounts receivable, inventory, and accounts payable balances, and this tool returns days sales outstanding, days payable outstanding, and days inventory outstanding, plus a cash conversion cycle visualization showing how cash moves through the business. The ratio definitions trip most users up: DSO divides by sales, but DIO and DPO divide by cost of goods sold, so feeding revenue into all three inflates DIO and DPO. A second surprise is that a negative cash conversion cycle is good: it means customers pay before supplier invoices come due.
Worked example
A concrete input and expected output from the current implementation.
Input
Accounts receivable $100,000; credit sales $1,000,000; inventory $150,000; COGS $600,000; accounts payable $120,000; period 365 days
->
Expected output
DSO 36.5 days, DIO 91.25 days, DPO 73 days, cash conversion cycle 54.75 days (about 55 days). The timeline shows cash committed for roughly 55 days: 91 days in inventory plus 37 days awaiting customer payment, offset by 73 days of supplier credit.
Each ratio divides its balance by its activity base and scales to 365 days: 100,000/1,000,000 x 365 = 36.5; 150,000/600,000 x 365 = 91.25; 120,000/600,000 x 365 = 73. The cycle is DIO + DSO - DPO: 91.25 + 36.5 - 73 = 54.75 days, the time cash is committed before customers pay.