Short answer

• Seed / pre-seed rounds in Australia: investors typically take roughly 10–25% of the company.
• Series A: typically 15–30% for the new A round (often leaving institutional VCs owning a meaningful minority stake).
• Very early pre-seed / angel tickets can be smaller (5–10% each), while large seed checks or lead VC commitments can push toward the higher end.

Why those ranges vary

• Stage and ticket size: earlier / smaller checks → smaller percentage per investor; a single large lead check → larger stake.
• Pre-money valuation: the higher the valuation you negotiate, the less equity you give away for the same cash.
• Syndication: multiple investors split the round, so each takes less.
• Investor type / expectations: VCs expect board seats and governance, angels or micro-funds often take less and are less demanding.
• Structure: convertible notes / SAFEs often defer valuation so initial percent is undefined until conversion; priced rounds fix percent immediately.
• Traction, team and sector: strong traction and hot sectors command higher valuations (lower dilution).

Common practical rules founders see in Australia

• Founders often aim to give no more than ~10–20% at pre-seed/seed to preserve runway for future rounds.
• A Series A that raises one or two institutional VCs will typically dilute founders another ~15–25% at that round.
• After 2–3 rounds founders commonly end up owning 30–60% collectively depending on how much capital was raised and on hiring/options.

Negotiation and planning tips

• Model cap table scenarios (best / base / worst) showing ownership after 3–4 rounds.
• Consider lead investors who bring follow-on capital to avoid heavy dilution from many one-off investors later.
• Use convertible instruments to delay valuation if you expect a meaningful value inflection soon.
• Reserve a realistic option pool (10–20%) — note investor requests for pool size are usually applied pre-money, which increases founder dilution if not planned for.

If you want, I can:

• Build a simple cap-table model with example rounds (pre-seed → seed → Series A) showing ownership and dilution.
• Summarize recent Australian market data if you’d like numbers from local industry reports (I can look those up).