Free online Cost Basis Calculator for stock investments. Supports multiple purchases, dividend reinvestment, and stock split adjustments. Pure frontend computation. | No signup · Data never leaves your device
Zero dependencies · Works offlineEnter one purchase per line in format: shares price (space or comma separated). Example:
100 50
200 55
150 52
For stock splits, enter the split ratio (e.g., 2 for 2:1).