18 LPA is where SIP finally feels serious — and lifestyle inflation kills it fastest. On fixed-heavy metro packages, in-hand often lands ₹1.1–1.3L/month. After rent at 30–35%, you still have headroom for ₹25–40k SIP if you automate on payday.
SIP math on 18 LPA in-hand
Do not SIP on CTC ÷ 12. Run fixed pay through a take-home calculator, subtract rent and essentials, then target 15–20% of in-hand for equity SIP. At ₹1.2L in-hand, that is ₹18–24k/month — enough to build ₹1 crore over 12–15 years at 12% CAGR if you step up on raises.
- Fixed-heavy 18 LPA metro in-hand: often ₹1.1–1.3L/month after PF and tax.
- Conservative SIP: ₹18–28k/month if rent is controlled.
- Aggressive SIP: ₹30–40k/month if you live with roommates or in Tier-2.
- Start with ₹10k if you must — zero SIP while waiting for the perfect amount is the real trap.
The takeaway
Automate SIP the same day salary hits. The month you upgrade rent or phone EMI before investing is when 18 LPA stops compounding.