Stock Portfolio Value Calculator

30,000 + 25,000 + 18,000 + 12,000 = 85,000 portfolio. Largest position 35%; moderate concentration. Quick snapshot useful before deciding on new purchases or portfolio rebalancing.

Portfolio tracker.

A worked example

Suppose you hold four stock positions with current values of 30,000, 25,000, 18,000, and 12,000 in your chosen currency. Enter these into the calculator. The tool returns a total portfolio value of 85,000. Your largest holding (the 30,000 position) represents 35% of the total—a moderate concentration level. If you then add a new purchase of 10,000 to position 1, the portfolio grows to 95,000, and the concentration of the largest position drops to 42%. The calculator updates instantly as you adjust any figure, letting you model the effect of rebalancing or new trades without switching between tools.

What moves the number most

The total portfolio value responds directly to changes in Position 1 Value, Position 2 Value, Position 3 Value, and Position 4 Value. A percentage increase in any position increases the total by that same percentage amount. The concentration ratio (largest holding as a percentage of total) is most sensitive to shifts in the largest position itself—doubling the largest position while keeping others fixed will significantly raise concentration.

The formula behind this

The calculator performs a simple sum of all four position values. It then identifies the single largest position and divides it by the total to express concentration as a percentage. Everything the calculator does is shown in the formula box below, so you can check the math against your own spreadsheet if you want.

Common scenarios where this matters

• Before adding a new stock purchase, to see how it will reshape overall concentration
• When assessing whether a single holding has grown too large relative to your plan
• For annual portfolio reviews, to track how positions have drifted from their original allocation
• When deciding whether to trim winners or add to smaller positions

What this captures and what it doesn't

The calculator shows your current total market value and concentration risk—the degree to which your portfolio is dependent on a single holding. It does not account for the sector or industry overlap between holdings, correlation during market stress, dividend income, fees, taxes on gains, or unrealised losses. Current values are a snapshot; they do not predict future performance or volatility. The concentration percentage is useful for identifying lopsided positions, but concentration alone does not measure diversification quality or risk.

For learning purposes

This calculator is designed for educational illustration. It models a simplified portfolio composition based on inputs you supply. Results do not constitute investment advice or a forecast of future outcomes.