100 envelope challenge
Number 100 envelopes from 1 to 100. Each one holds its number in dollars. Fill them all and you have saved $5,050.
How it works
You start with 100 envelopes numbered 1 to 100. Each time you save, you pick an envelope at random, put in the amount written on it and mark it done. Envelope 7 gets $7; envelope 83 gets $83. The order is up to you, which is what makes it feel more like a game than a budget line.
Why the total is $5,050
The sum of the numbers from 1 to 100 is 100 × 101 ÷ 2 = 5,050. So the full challenge saves exactly $5,050, no matter in which order you fill the envelopes.
Totals for common versions
Full challenge, $1 per number: 5,050
Half version, $0.50 per number: 2,525
Double version, $2 per number: 10,100
50 envelopes (1 to 50): 1,275
How long does it take?
The popular version is 100 days, one envelope a day. That means about $50 a day on average, or roughly $1,500 a month, which is a lot for most budgets. Two envelopes a week stretches it over 50 weeks: about $101 a week on average. For many people the half version over a year is the realistic one, about $49 a week.
The weekly cost is never even. A week with envelopes 92 and 97 costs $189; a week with 3 and 11 costs $14. If your pay is the same every week, mix one high and one low number each time to keep the total close to the average.
Tips that make it work
- Skip the cash if it is not safe. Keeping $5,000 in envelopes at home is a risk. Draw the envelope number, then transfer that amount to a savings account and mark it on a chart.
- Use a printable 1–100 grid. Color each number when you deposit it. Seeing the grid fill up is the motivation.
- Start with the big numbers when money is easier, for example right after a paycheck, a tax refund or a bonus.
- Pick a fixed day, like every payday, and set a reminder.
- Decide the goal before you start. A named goal (emergency fund, vacation, a car repair fund) makes the hard weeks easier.
Which version should you choose?
Look at what you can save per week without borrowing. Multiply by 52 and compare with the totals above. If you can set aside about $50 a week, the half version fits. If you can manage about $100, the full challenge fits over a year. If neither fits, the 52-week challenge ($1,378 at $1 per week) is a gentler start.
The savings challenge calculator shows the year total, the average per week and per month and the end date for any multiplier. For a side-by-side of every challenge, see which savings challenge to pick for 2027.
Frequently asked questions
How much do you save with the 100 envelope challenge?
$5,050 when each envelope holds its number in dollars. The half version saves $2,525 and the double version $10,100.
Can I do the 100 envelope challenge in a year?
Yes. Two envelopes a week for 50 weeks finishes it in about a year, at an average of about $101 a week. The half version averages about $49 a week.
Do I need real envelopes?
No. Many people draw a number, transfer that amount to a savings account and color the number on a printable 1 to 100 chart. It avoids keeping cash at home.
General information, not financial, tax or legal advice. Examples use made-up numbers.
Savings Challenge Bundle 2027
The 100 envelope, 52-week, $5K and paycheck challenges in one sheet, with a printable grid that colors in as you go.