cgt share calculator

What is a CGT share calculator?

A CGT share calculator helps you estimate the tax impact of selling shares. In Australia, when you dispose of shares at a profit, you may create a capital gain. That gain can be reduced by allowable costs, carried-forward capital losses, and potentially a CGT discount if eligibility rules are met.

This calculator gives you a fast estimate so you can make better decisions before you sell. It can be useful for planning parcel sales, timing disposals, and understanding how brokerage and prior losses change your final tax position.

How this calculator works

The logic follows a simplified version of common CGT steps:

• Capital proceeds = shares sold × sell price per share − sell brokerage
• Cost base = shares bought × buy price per share + buy brokerage + other costs
• Gross capital gain/loss = capital proceeds − cost base
• Net capital gain before discount = gross gain − carried-forward capital losses
• Discounted gain applies only if holding period and taxpayer rules are satisfied
• Estimated CGT = taxable gain × your marginal tax rate

If your sale produces a capital loss, you generally do not pay CGT on that disposal. Instead, the loss may be carried forward to offset future capital gains.

CGT discount rules at a glance

• Individuals and many trusts: generally 50% discount when asset held for at least 12 months.
• Complying super funds: generally 33.33% discount when eligible.
• Companies: typically no CGT discount.

Real tax outcomes can vary with residency, trust structures, record-keeping quality, and special events (demergers, return of capital, inheritance, and corporate actions).

Step-by-step example

Suppose you sold 1,000 shares at $15.00 each, originally purchased at $10.00 each. You paid $20 brokerage on buy and $20 on sell, held for 24 months, and have $1,200 in prior capital losses.

• Capital proceeds = 1,000 × 15.00 − 20 = $14,980
• Cost base = 1,000 × 10.00 + 20 = $10,020
• Gross gain = $4,960
• After losses = $4,960 − $1,200 = $3,760
• 50% discount (individual, 12+ months) = taxable gain $1,880
• At 34.5% tax rate, estimated CGT ≈ $648.60

That rough estimate can help you compare selling now versus later, or selling in one tax year versus splitting parcels across years.

What to include in your share CGT records

Accurate records matter. Even a small missing fee can change your taxable gain, especially across multiple parcels. Keep a clean audit trail of:

• Contract notes for every buy and sell
• Brokerage and platform fees
• Corporate actions (splits, consolidations, demergers)
• Dividend reinvestment transactions (DRP)
• Any prior-year capital losses reported in tax returns

Parcel selection strategy

If you acquired shares in several parcels, your chosen parcel can materially change your gain. Investors often review tax outcomes under different methods before placing orders. A quick pre-trade estimate can prevent surprises at year end.

Common mistakes investors make

• Forgetting brokerage in cost base or proceeds
• Applying the CGT discount when held less than 12 months
• Ignoring carried-forward losses
• Using the wrong taxpayer discount assumptions
• Treating this estimate as final tax advice without professional review

How to use this tool for planning

Try multiple scenarios before selling:

• Change sell price to test optimistic and conservative outcomes
• Compare sale timing before and after 12 months of holding
• Model the effect of prior losses on current gains
• Check impact of your marginal tax bracket

Used well, a CGT calculator helps with portfolio rebalancing, tax-aware selling, and cash-flow planning for tax liabilities.

Final note

This cgt share calculator is designed to be practical and easy to use. It provides a solid estimate, not a substitute for tailored advice. If you have large gains, complex trust structures, foreign tax credits, or unusual corporate actions, consult a registered tax professional before lodging your return.