How to calculate On-Balance Volume
If Close > Previous close: OBV = Previous OBV + Volume
If Close < Previous close: OBV = Previous OBV − Volume
If equal: OBV = Previous OBV
Paste prices oldest-first, one value or row per bar — straight from a spreadsheet or CSV export. Use “Sample data” to try it instantly.
Worked example
- Closes 10 → 11 → 10 → 10 with volumes 100, 200, 300, 400.
- OBV: 0 → +200 → −100 → −100.
How to interpret On-Balance Volume
The level of OBV is arbitrary — its direction is what matters. Rising OBV with flat price hints at accumulation; falling OBV while price rises warns that the advance lacks volume support. Compare with Chaikin Money Flow, which also weighs where the close sits in the bar.