Cheng Calculator: Compound Habit Earnings & Net Growth
Estimate how regular investing habits can grow over time with compounding.
What is the Cheng Calculator?
The Cheng Calculator is a practical planning tool for long-term wealth building. Here, CHENG stands for Compound Habit Earnings & Net Growth. It combines five levers that matter most in personal finance: starting balance, monthly contributions, return rate, time horizon, and contribution growth.
Instead of guessing whether your investing habit is “enough,” this calculator helps you see a concrete projection. You can quickly compare different scenarios and spot where small behavior changes create big outcomes.
How to use it effectively
1) Start with your real numbers
Enter your current investable balance and monthly contribution. Accuracy matters less than consistency: even rough numbers are useful if you review and update them regularly.
2) Use a conservative return assumption
For long-term equity-heavy portfolios, many planners use 6%–8% nominal as a rough estimate. If you prefer caution, test 5% and compare it against your base case.
3) Model increasing contributions
Real life is not static. Income usually rises over time, so contributions can rise too. Even a 1%–3% annual increase can significantly lift your ending balance.
What the results mean
- Future Value: your projected portfolio at the end of the chosen period.
- Total Contributions: the amount you personally put in.
- Investment Growth: gains created by compounding beyond your direct contributions.
- Inflation-Adjusted Value: future value translated into today’s purchasing power.
- Estimated Monthly 4% Withdrawal: a simple retirement-income reference point.
Example: coffee money to capital
Suppose you invest $200 per month instead of spending it on small daily extras, start with $1,000, and earn 7% for 20 years. The projection often surprises people: the majority of the final amount tends to come from time and compounding, not from dramatic one-time moves.
Common planning mistakes to avoid
- Using unrealistic return expectations.
- Ignoring inflation when setting long-term goals.
- Keeping contributions flat even as income rises.
- Changing strategy too often after short-term market moves.
Final thought
The Cheng Calculator is not a prediction machine; it is a decision tool. Use it to build better habits, stress-test your plan, and make progress measurable. Small, repeatable actions can outperform perfect timing.