Lunch Cost Calculator

The Lunch Cost Calculator shows you the real yearly cost difference between buying lunch out and packing a lunch from home — and exactly how much you could save each year. Enter what you spend on a bought lunch, what a packed lunch costs you, and how often you eat out, and the tool breaks the savings down by day, week, month, and year. It then goes one step further with an "invest the difference" projection that shows what those small daily savings could grow into over 5, 10, 20, and 30 years.

Why Lunch Costs Add Up So Fast

A bought lunch rarely feels expensive on its own — it is "just" a few dollars, euros, or pounds. The problem is repetition. A small daily gap, multiplied by five days a week and roughly fifty weeks a year, quietly turns into a four-figure sum. This calculator makes that hidden total visible so you can decide whether the convenience of buying out is worth the price.

Lunch Savings Formula

The calculation is simple and transparent. First find how many lunches you buy in a year, then multiply by the cost of each option, and finally take the difference.

In Step 3, PMT is the amount you save each month, i is the monthly return (annual return ÷ 12), and n is the number of months. This is the standard future-value-of-an-annuity formula, the same one used by retirement and savings calculators.

Example: Bought Lunch vs Packed Lunch

In this example, packing lunch saves about 1,920 per year. Invested at a 7% annual return, that habit could grow to roughly 195,000 over 30 years — from lunch money alone.

Tips to Cut Your Lunch Costs

• Batch cook: Make extra dinner and pack the leftovers — near-zero extra effort for a free lunch.
• Prep on Sunday: Assembling five lunches at once is faster and cheaper than buying five times.
• Keep a backup: Stock a few shelf-stable lunches at work so a busy morning never forces a purchase.
• Set a "buy out" budget: Allow yourself one or two bought lunches a week instead of going cold turkey — it is more sustainable.
• Invest the difference automatically: Move your weekly savings into an investment or savings account so it actually compounds.

How to Use This Calculator

1. Enter your lunch costs: Pick your currency, then enter what a bought lunch costs and what a packed lunch costs you.
2. Set your routine: Choose how many days a week you buy lunch and how many working weeks you have per year.
3. Add an investment return (optional): Enter an expected annual return to see what your savings could grow into.
4. Click Calculate: Review your daily, weekly, monthly, and yearly savings, plus the long-term projection and step-by-step math.

Frequently Asked Questions

How much can you save by packing your lunch?

It depends on the gap between buying out and packing. A common example is spending 12 on a bought lunch versus 4 to pack one. Over 5 days a week and 48 working weeks that is a difference of about 1,920 per year. The Lunch Cost Calculator works out the exact figure from your own numbers.

How is the yearly lunch cost calculated?

The yearly cost is the cost of one lunch multiplied by the number of lunches per year, where lunches per year equals the days per week you buy lunch multiplied by the working weeks per year. Yearly savings is the yearly cost of buying out minus the yearly cost of packing.

What does the invest-the-difference projection mean?

Instead of spending the difference, you pack your lunch and invest the money you save each month. The projection uses the standard future value of a recurring monthly contribution to estimate what those savings could grow to after 5, 10, 20, and 30 years at the annual return you choose.

How many working weeks should I use per year?

A full year is 52 weeks, but most people take some holiday and public holidays, so 48 weeks is a realistic default for a typical job. Use 52 if you want the gross figure, or fewer weeks if you work part of the year.

Is packing lunch always cheaper than buying out?

Almost always. Even accounting for groceries, a home-packed lunch usually costs a fraction of a restaurant or cafe lunch. The savings are largest when you currently buy lunch out several days a week. If your packed lunch costs more than buying out, the calculator will tell you.

Additional Resources

• Brown-bag Lunch - Wikipedia
• Future Value - Wikipedia