How Much Can You Buy for Your Money?
Enter a budget and up to five prices to see how many shares, ETF units, or crypto your money buys at each — and how many more or fewer units a higher price costs.
What this calculator shows
It divides your budget by each price to show the units you get, then compares them against a baseline. Because units = budget ÷ price, a higher price always buys fewer units — but by less than the price rose. Prices are what you enter; fees, commissions, and spreads are not modeled.
Inputs
Set your budget, add up to five prices, and pick which one to measure the others against.
The amount you have to invest.
Buying mode
Allow fractional units (crypto & many brokers) — the whole budget goes in.
Prices
Share or bookmark this scenario.
- Units at baseline
- 0.2222
- Cheapest vs priciest
- +0.0025
- Biggest gap vs baseline
- +$2.25
Price A · $900.00
Extra units at the lowest price
1.1% · +0.0025 units
- Units at each price
- Your prices
The inverse curve: units rise steeply at low prices and flatten as price climbs, so each step up in price costs fewer and fewer units.
- Units you get
Units per option side by side. A higher price is a shorter bar — fewer units for the same budget.
Price comparison
Every option side by side: units you get, and how each compares with the baseline.
| Option | Price | Units you get | Δ vs baseline | Δ value |
|---|---|---|---|---|
| Price ABaseline | $900.00 | 0.2222 | — | — |
| Price B | $890.00 | 0.2247 | +0.0025 (1.1%) | +$2.25 |
Your $200.00 buys 0.2222 units at Price A — up to +0.0025 more at the cheapest price here, all under these assumptions.
Opportunity cost of waiting
Buying at $890.00 instead of $900.00 — a 1.1% lower price — would have bought 0.0025 more units with the same $200.00, worth about $2.25. That is the opportunity cost of buying at Price A instead.
How the prices compare
At $900.00 you get 0.2222 units. At $890.00 you get 0.2247 — +0.0025 units (1.1% more) for a lower price — worth about $2.25 at the baseline price.
Why the change is smaller than the price
A 10% higher price costs about 9.1% fewer units — because units = budget ÷ price, the unit change is always smaller than the price change.
Fractional vs whole units
Fractional units let your whole budget go in, so no cash is left stranded by a high unit price — the way crypto and many brokers now work.
Small differences rarely matter
Small price differences barely change how much you own — one reason dollar-cost averaging tends to beat waiting for the perfect dip.
Unit differences are most meaningful when comparing the same asset at different prices. Across different assets, compare what each budget buys rather than the difference between them.
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Try the Dollar Cost Averaging CalculatorHow this calculator works
An educational look at the arithmetic of a fixed budget — not a forecast and not an order preview. It divides your budget by each price and compares the results.
Units = budget ÷ price
The number of units you can buy is your budget divided by the price per unit. A higher price buys fewer units of the same asset.
The relationship is non-linear
Because units are the inverse of price, the drop in units is always smaller than the rise in price: a 10% higher price is about 9.1% fewer units, not 10%.
Fractional vs whole units
Crypto and many brokers allow fractional buys, so the whole budget goes in. Whole-only buying rounds down and can leave cash idle — $200 buys 0 whole shares of a $900 stock.
Works for any asset
Stocks, ETF units, and crypto all follow the same math. Enter any price and the calculator shows what your budget buys.
Fees are not included
This tool ignores fees, commissions, spreads, and slippage. Those costs would reduce the units you actually receive, so treat the figures as an educational baseline.
This is one of several educational models on Rionux. See how we model these projections across all our tools.
Buying shares and crypto with a fixed budget
The same simple math — budget ÷ price — answers both of the most common versions of this question.
How many shares can I buy?
To find how many shares a budget buys, divide the amount by the share price. With $1,000 and a $45 share, that is about 22.2 shares. If your broker supports fractional shares, you can buy all 22.2 and put the whole $1,000 to work. If it only allows whole shares, you buy 22 and roughly $10 stays in cash. The higher the share price relative to your budget, the more that whole-share rounding matters — $200 buys 0 whole shares of a $900 stock, leaving the entire budget uninvested.
How much crypto can I buy?
Crypto uses the identical formula, units = amount ÷ price, and is almost always fractional. With $200 and a coin priced at $60,000 you can buy about 0.00333 of it; with $50 and a $2.50 token you get 20 tokens. Because fractional amounts are allowed, none of your budget has to sit idle — which is why the whole-units caveat that affects some stocks rarely applies to crypto.
Common mistakes to avoid
- Assuming a 10% higher price means 10% fewer units. It is about 9.1% fewer — the unit change is always smaller than the price change.
- Forgetting whole-share limits. Rounding down can leave a surprising amount of cash uninvested when the price is high relative to your budget.
- Over-optimizing tiny dips. A small price difference barely changes how much you own, so waiting for a perfect entry rarely pays off.
- Ignoring fees. Commissions, spreads, and slippage are not modeled here and would reduce the units you actually receive.
Related concepts
Keep exploring how a fixed budget turns into units over time.
Frequently asked questions
Common questions about buying shares and crypto with a set amount of money.
How many shares can I buy with $X?
Divide your budget by the share price: shares = amount ÷ price. With $200 and a $900 share, that is 0.22 shares if your broker allows fractional buying, or 0 whole shares with all $200 left uninvested if it does not. With $1,000 and a $45 share it is about 22.2 fractional, or 22 whole shares with roughly $10 left over. Enter your own budget and price above to see the exact figure.
How much crypto can I buy with $X?
The same way: units = amount ÷ price. Crypto is almost always fractional, so $200 at a $60,000 coin buys about 0.00333 of it, and $50 at a $2.50 token buys 20 tokens. Because fractional amounts are allowed, none of your budget has to sit idle. Turn on fractional units above and enter the price to see how much your money buys.
Does a higher price mean I get fewer shares?
Yes — for the same budget, a higher price always buys fewer units, because units are the budget divided by the price. The relationship is not one-for-one, though: the drop in units is always smaller than the rise in price. A 10% higher price costs you about 9.1% fewer units, not 10%.
What are fractional shares?
Fractional shares let you buy part of a share rather than a whole one, so a fixed budget can be fully invested even in a high-priced stock. Many brokers now support them, and crypto is fractional by design. Without fractional buying, whole-share rounding can leave part of your budget uninvested — for example $200 buys 0 whole shares of a $900 stock, leaving all $200 in cash.
Does buying at a slightly higher price really matter?
Usually far less than people expect. Because units = budget ÷ price, a small price difference changes how much you own by even less than the price moved — a 2% higher price is only about 2% fewer units. Over a long horizon of regular buys, these small differences tend to wash out, which is one reason dollar-cost averaging is often preferred to waiting for a perfect entry.
Does this calculator include fees or commissions?
No. It shows the arithmetic of budget ÷ price only, and deliberately ignores fees, commissions, spreads, and slippage. Those costs would reduce the number of units you actually receive, so treat the output as an educational baseline rather than an exact order preview.
Can I compare different assets, not just prices?
Yes, you can enter any labels and prices. Keep one caveat in mind: the unit difference between entries is most meaningful when they are the same asset at different prices. Across genuinely different assets, one unit of each is not comparable, so read what each budget buys on its own rather than the difference between them.
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Educational use only
Educational purposes only. Calculator results are estimates based on assumptions and user inputs. They are not financial, investment, legal, or tax advice. Investing involves risk, including possible loss of principal. Past performance does not guarantee future results.