How to use the Lunch Savings Calculator
Enter your typical eating-out lunch cost, your homemade packed lunch cost, the number of workdays per year, your intended investment period, and an estimated annual return rate. The calculator shows your daily and annual savings, the simple total over N years, and the compounded total if you invest that money each year. The extra gain column shows how much more compound investing earns compared to simply saving the cash.
The latte factor applied to lunch
Author David Bach popularized the idea that small recurring expenses — like daily coffee or lunch — represent major long-term wealth when redirected to investments. Saving $10/day invested at 7% annually grows to roughly $525,000 over 30 years. This calculator lets you see your specific numbers in minutes.
Frequently Asked Questions
Include only food ingredients — typically $2–4 per serving in the US. Don't add containers or utilities since those costs are negligible. If you batch-cook on Sundays, per-meal cost drops even further, often under $2.
No. Bringing lunch just 3 days per week instead of 5 still saves about 60% of the maximum. Even partial adoption compounds significantly over years. Start with the days you eat alone and build from there.