Forex bonus math is what separates traders who profit from bonuses and traders who pay more than the bonus was ever worth. Every offer has a hidden cost buried in the turnover requirement, and that cost is measurable in dollars. This article shows the full arithmetic with three worked examples — a no-deposit bonus, a deposit bonus, and cashback — so you can evaluate any offer in five minutes with a calculator.
For a broader look at whether bonuses make sense, read are forex bonuses worth it?. For strategy after you have decided to claim, see how to use a forex bonus wisely.
Verified June 2026. forex-bonus.com may earn a commission through broker links. This never influences our ratings. Trading forex carries significant risk — most retail traders lose money. See our full affiliate disclosure and risk warning.
Important: Forex bonuses are banned for retail clients in the EU (ESMA), UK (FCA), Australia (ASIC), and the US. This guide applies to traders in eligible regions — primarily emerging markets in Africa, Asia, the Middle East, and Latin America — where regulated brokers legally offer bonus programs.
The Core Formula
Every forex bonus requires you to trade a certain volume before withdrawal. Trading is not free — every round-trip trade costs you the spread (and sometimes a commission). The fundamental equation:
Net Bonus Value = Bonus Amount - (Required Lots x Cost Per Lot)
Positive means the bonus pays you. Negative means you are paying the broker more than the bonus gives.
Cost per lot combines spread and commission. On EUR/USD, a standard account with a 1.5-pip spread costs approximately $15 per standard lot (100,000 units). An ECN account with a 0.8-pip spread plus $7 round-trip commission costs roughly the same: $8 + $7 = $15. We use $15 per lot as the baseline throughout. Calculate your exact cost with our turnover calculator.
Worked Example 1: $30 No-Deposit Bonus
Terms: $30 bonus, 5 standard lots required, 30-day limit, $100 profit cap, profits only withdrawable (bonus itself is non-withdrawable). These are realistic conditions — verify current offers through our bonus finder.
Spread cost: 5 lots x $15 = $75
The spread cost alone is $45 more than the bonus. On paper, a net loss. But with NDBs you risk zero of your own capital — the $75 comes out of the bonus balance and trading profits, not your pocket. The real question: can you trade profitably enough to cover the spread drag?
| Outcome | Trading P&L (Before Spreads) | Spread Cost | Net Result | Withdrawable |
|---|---|---|---|---|
| Break-even trading | $0 | -$75 | -$75 | $0 (wiped) |
| Modest profit | +$120 | -$75 | +$45 | $45 |
| Strong profit | +$200 | -$75 | +$125 | $100 (capped) |
Verdict: The $30 NDB is a low-stakes learning tool, not a money-maker. The worst outcome is walking away with nothing — which is where you started. Best case is $100 (the typical cap). The expected value for an average trader is close to zero, but the key advantage is that the downside is also zero because you never deposited your own funds.
When it works: You were going to open an account anyway and want to test live execution, slippage, and withdrawal speed before committing real money.
When it does not work: You treat $30 as “free money.” It is not. It is conditional permission to trade with broker capital under restrictive terms.
Use our bonus calculator to run numbers on any specific NDB.
Worked Example 2: $500 Deposit Bonus (100% Match)
Terms: $500 deposit, $500 bonus (100% match), $1,000 total capital, 30 standard lots required (~6x the bonus), 90-day limit, bonus removed if you withdraw before completing turnover.
Spread cost: 30 lots x $15 = $450
Net bonus value: $500 - $450 = +$50
Slim margin. And that $50 assumes you trade only major pairs at typical spreads. Trade exotic pairs (USD/ZAR, USD/TRY) where spreads reach 50-100 pips, and the same 30 lots cost $1,500-$3,000 — destroying the bonus several times over.
Break-even formula:
Break-Even Cost Per Lot = Bonus Amount / Required Lots
$500 / 30 = $16.67 per lot
If your actual cost is below $16.67, the bonus is net positive. Above that, it costs you money. This is the single most important number to calculate before claiming any deposit bonus.
Same Bonus, Different Terms
The percentage is irrelevant. The lot requirement is everything.
| Scenario | Required Lots | Spread Cost | Net Value | Break-Even/Lot | Verdict |
|---|---|---|---|---|---|
| Low requirement | 5 lots | $75 | +$425 | $100.00 | Excellent |
| Moderate | 15 lots | $225 | +$275 | $33.33 | Good |
| High | 30 lots | $450 | +$50 | $16.67 | Marginal |
| Extreme | 50 lots | $750 | -$250 | $10.00 | Net loss |
Read deposit bonus terms explained for the full breakdown of conditions brokers attach to these offers.
Worked Example 3: Cashback — $5/Lot Over 6 Months
Cashback is structurally different. No lump sum, no turnover gate, no deadline. You earn a fixed amount back on every lot, indefinitely.
Terms: $5 per standard lot, 3 lots per week (active but not excessive), 6-month period (26 weeks).
Total lots: 3 x 26 = 78 lots
Total cashback: 78 x $5 = $390
No requirement to unlock this. Every lot earns $5 back. Your effective spread cost drops from $15 to $10 per lot — a 33% reduction in trading costs.
Cashback vs. Deposit Bonus Over Time
Same trader (3 lots/week). $500 deposit bonus (30-lot requirement) vs. $5/lot cashback.
| Period | Deposit Bonus (Net) | Cashback Earnings |
|---|---|---|
| Month 1 | +$50 (one-time) | $60 |
| Month 3 | +$50 (already earned) | $180 |
| Month 6 | +$50 (same) | $390 |
| Month 12 | +$50 (same) | $780 |
By month two, cashback surpasses the deposit bonus. By month twelve, it outearns it more than 15 to 1. For active traders, cashback is the mathematically superior structure. The only risk is choosing a broker or IB partner that does not actually pay — which is a trust and verification issue, not a math issue.
Break-Even Reference Table
Before claiming any bonus, find the closest match below. If your broker’s actual cost per lot (spread + commission) exceeds the break-even number, the bonus costs you money.
| Bonus | Required Lots | Break-Even Cost/Lot |
|---|---|---|
| $30 NDB | 3 lots | $10.00 |
| $30 NDB | 5 lots | $6.00 |
| $50 NDB | 5 lots | $10.00 |
| $100 NDB | 10 lots | $10.00 |
| $200 deposit | 10 lots | $20.00 |
| $500 deposit | 15 lots | $33.33 |
| $500 deposit | 30 lots | $16.67 |
| $500 deposit | 50 lots | $10.00 |
| $1,000 deposit | 30 lots | $33.33 |
| $1,000 deposit | 50 lots | $20.00 |
Run exact numbers through our bonus calculator.
When the Math Works vs. When It Does Not
The math usually works when:
- Cashback rebates — any amount is pure savings with no volume gate
- Deposit bonuses with low multipliers (3x-5x the bonus) and competitive spreads
- NDBs treated as no-deposit practice rather than income
- You were already going to trade the required volume through normal activity
- Time limits are generous (60+ days), so you trade at your normal pace
The math usually does not work when:
- Turnover exceeds 8-10x the bonus — spread cost almost always exceeds the bonus at $12-$18/lot
- You must change your behavior to meet the requirement (larger sizes, more trades, unfamiliar pairs)
- Time limits are short (7-14 days) for large volume, creating pressure to overtrade
- Profit caps are below the spread cost — you cannot mathematically come out ahead
- You trade exotic pairs where 30-100 pip spreads make requirements 3-7x more expensive
The Behavioral Cost Nobody Calculates
The formulas above cover the financial math. But there is a second cost that never appears in a spreadsheet: the behavioral cost of chasing a target.
When a trader has a bonus deadline and a volume requirement, their decision-making shifts. They enter trades they would normally skip. They increase position sizes to “get through the lots faster.” They hold losing trades longer because closing and reopening adds spread cost. They trade volatile news events they would otherwise avoid.
A bonus that is mathematically marginal — say +$50 net value on a $500 deposit match — can easily become a net loss if the deadline pressure causes even one or two poor decisions. A single bad trade on a standard lot can wipe out $200 or more.
The practical rule: only claim bonuses where the required volume fits comfortably within your normal trading activity, with room to spare. If meeting the requirement means trading differently than you otherwise would, the bonus is not worth it — regardless of what the formula says. The math must work and your behavior must stay unchanged.
Frequently Asked Questions
How do I calculate the real cost of a forex bonus?
Multiply the required trading lots by your cost per lot (spread in pips times $10 per standard lot, plus any commission). Subtract that total from the bonus amount. Positive means value; negative means the bonus costs more than it gives. Use our bonus calculator for instant results.
Is a no-deposit bonus ever worth claiming?
Yes, when you treat it as a free platform test rather than income. You risk zero of your own money, so the worst case is walking away with nothing. Expected withdrawable profit is typically small (under $50), but as a way to experience live trading conditions before depositing, the math supports it.
Why does cashback almost always beat a deposit bonus?
Cashback has no volume threshold. Every lot earns the rebate immediately with no deadline or minimum. A deposit bonus is one-time and must be “earned” through volume whose spread cost often consumes most of the bonus. Cashback compounds; deposit bonuses do not.
What is a fair turnover requirement for a deposit bonus?
Below 5x the bonus amount is favorable. At 5x and $15/lot, your spread expenditure is roughly 15% of the bonus, leaving 85% as genuine value. Above 8-10x pushes break-even below $10-$12 per lot, which is hard to achieve on most account types. Anything above 10x is almost always a net loss.
The Bottom Line
Forex bonus math is straightforward once you have the framework: bonus value minus spread cost of the required volume equals the real value of the offer. Most traders never run this calculation, which is exactly why the bonus industry thrives on impressive-sounding percentages that quietly cost traders more than they give.
Run the numbers on every offer before you claim. Use the break-even table as a quick filter, or plug exact terms into our bonus calculator for a precise answer. And if you plan to trade actively for more than a few months, cashback programs will almost always deliver more total value than any one-time bonus — no matter how large the headline figure.
Tim Morris has analyzed hundreds of forex bonus offers since 2017, identifying which deliver genuine value and which are better declined.