Whats the difference between Avg Gas Cost per call (BNB) and Avg Gas price (Gwei) like the screenshot i attached

this screenshot is from Binance Smart Chain Mainnet Gas Cost and usage and other analytics.

whats the difference between the two graphs i circled? i thought the difference was just the units (one in Gwei, one in BNB), but when i tried to convert between the two i dont get the same Avg Gas costs per call

Transaction Average Cost - Gas Cost/Call BNB - This means the average transaction fee in BNB.

Gas Unit Price By Date, GWei - Avg. Gas Price, GWei - This means the average price of per Gas unit in Gwei.

Transaction fee = Gas unit * Gas price per unit