Weighted Average Calculator
Calculate a weighted average or the arithmetic totals of up to three purchase lots.
Weighted mode: sum(value × weight)/sum(weight), up to 30 rows. Lot mode: Q=sum(units), C=sum(units × price), average=C/Q; value=Q × current price; profit=value−C; return=100 × profit/C. Average and unit shares are undefined if Q=0; return is undefined if C=0. This is purchase arithmetic, not tax matching or a statutory pooled-cost calculation. Changing mode clears numeric rows and current price.
Inputs stay in this browser.
| Lot | Units | Price per unit (your currency) | Lot cost | Share of units (%) |
|---|
A QUICK WALKTHROUGH
How to use this tool
- Weighted mode: sum(value × weight)/sum(weight), up to 30 rows. Lot mode: Q=sum(units), C=sum(units × price), average=C/Q; value=Q × current price; profit=value−C; return=100 × profit/C. Average and unit shares are undefined if Q=0; return is undefined if C=0. This is purchase arithmetic, not tax matching or a statutory pooled-cost calculation. Changing mode clears numeric rows and current price.
Formula and limits
Weighted mode: sum(value × weight)/sum(weight), up to 30 rows. Lot mode: Q=sum(units), C=sum(units × price), average=C/Q; value=Q × current price; profit=value−C; return=100 × profit/C. Average and unit shares are undefined if Q=0; return is undefined if C=0. This is purchase arithmetic, not tax matching or a statutory pooled-cost calculation. Changing mode clears numeric rows and current price.
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Inputs stay in this browser.
GOOD TO KNOW
Common questions
Which rows are used?
Every displayed row must be complete. A zero-unit lot contributes zero cost and units.