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Why Your Broker P&L Differs From Your Calculator

A calculator gives you the clean, gross profit on a price move. Your broker deducts real costs and converts at a live rate, so the two rarely match to the cent.

Written by PipGauge editorial team

Reviewed by PipGauge methodology review

Last updated 2026-07-06

Short answer. A profit calculator returns the gross result of a price move. Your broker statement is net: it subtracts the spread, any commission and any overnight swap, and if your account currency differs from the quote currency it converts at a live rate. It also fills at fractional-pip prices rather than round numbers. Add those costs back and reconcile the rates, and the two figures line up — the gap is the cost of trading, not a calculator error.

What this page is for

Traders often assume a mismatch between a calculator and a broker statement means one of them is wrong. Usually neither is. This page lists the specific reasons the two diverge and shows how to reconcile them, so you can tell a normal cost from an actual pricing problem. It supports the profit and loss calculator, which gives the gross number this page then adjusts. Educational only, not advice.

How it works

Start from the gross profit a calculator gives you, then walk to the net figure your broker reports:

net P&L = gross P&L − spread cost − commission ± swap/financing, converted to account currency

Each term is real and separate (swap is the one that can go either way — a debit or a credit):

Spread — the gap between bid and ask. If you calculated from the mid price, it is missing from your gross figure.
Commission — on raw-spread accounts, a per-lot charge each side.
Swap / rollover — a financing debit or credit for holding past the daily rollover time.
Conversion rate — when your account currency differs from the quote currency, the result is converted at the live rate, which may differ from the one you typed.
Fractional pips and rounding — with most brokers, real fills land on pipettes rather than round numbers.

Inputs and assumptions

Standard lot = 100,000 units; EUR/USD pip value = $10 per standard lot.
Commission and swap figures below are illustrative examples — the real values come from your own account's contract and financing table.
Example prices and rates are round illustrations, not live quotes.
The reconciliation is arithmetic; it does not include slippage on fast markets or weekend price gaps, which widen the gap further.

Worked example 1 — spread and commission on a same-day trade

You buy one standard lot of EUR/USD and read the trade off the mid as 1.0800 to 1.0830 — a tidy 30 pips, so a quick calculator says 30 × $10 = $300. But your actual fills, including spread, were 1.08005 on entry (the ask) and 1.08300 on exit (the bid): 1.08300 − 1.08005 = 0.00295 = 29.5 pips, or 29.5 × $10 = $295. On a raw-spread account with a $7 round-turn commission, the statement shows $295 − $7 = $288. The $12 gap from your $300 is the half-pip spread ($5) plus commission ($7) — both real costs, neither a calculator fault.

Worked example 2 — account currency and an overnight hold

Now a trade with $150 of gross profit on the price move, held two nights, on a EUR account. Two things move the final number. First, swap: if your broker's financing shows a debit of about $2.10 per lot per night, two nights is roughly −$4.20, leaving about $145.80. Second, conversion: converting to euro at EUR/USD 1.0850 gives 145.80 ÷ 1.0850 = €134.38, whereas a calculator that assumed 1.0800 on the gross $150 would have shown 150 ÷ 1.0800 = €138.89. The statement comes in about €4.51 lower — partly the financing cost, partly because a smaller, later figure is converted at a different live rate. Add the swap back and match the rate, and it reconciles.

Common mistakes — why the number moves

Calculating from the mid price. The mid ignores the spread, so the broker's net always looks worse by that amount. Use your actual fills, or subtract the spread explicitly.
Ignoring commission on raw-spread accounts. A tight spread often comes with a per-lot commission; leaving it out overstates profit.
Forgetting swap on multi-day holds. One night is easy to miss; several nights are not, and the sign can be a credit or a debit.
Using a stale conversion rate. On a non-USD account the rate at close, not the rate you typed earlier, sets the converted figure.
Expecting the cent to match. Between pipette fills and rounding, a perfect match is unusual. Reconcile to within trading costs, not to zero.

Methodology and limitations

The reconciliation here is straightforward arithmetic and matches the gross output of our profit and loss calculator. Commission and swap values are illustrative; your real ones are in your account's contract and financing table. Example prices and rates are round illustrations, not live data, and the walk-through excludes slippage and weekend gaps, which can widen the difference. This is educational information for non-US retail traders, not investment, trading or financial advice. Always confirm figures against your own broker. Last updated 2026-07-06.

Frequently asked questions

Why is my broker profit lower than the calculator said?

Almost always because the calculator gave you gross profit on the price move, while the broker also took the spread, any commission and any overnight swap, and may have converted at a different rate. Add those costs back and the two usually reconcile. The spread cost calculator quantifies the spread part.

Does the spread get counted twice?

No, but it is easy to double-count in your head. If you calculate from the mid price you leave the spread out, so the broker's figure looks worse by the spread. If you calculate from your actual fill prices, the spread is already inside those prices and no separate deduction is needed.

Why does an overnight trade differ more?

Because of swap, also called rollover. Holding a position past the daily rollover time applies a financing debit or credit set by your broker. A single day is often small; several nights add up, and a plain profit calculator does not include it.

My account is not in USD — does that matter?

Yes. When your account currency differs from the quote currency, the profit is converted at a live rate. If your calculator used a slightly different rate, or the rate moved before you closed, the converted figure will differ. See how pip value changes by account currency.

Are pipettes and rounding part of the gap?

They can be. Most brokers quote fractional pips (pipettes, the fifth decimal), so your true fill might be 29.5 pips rather than a rounded 30. Small per-trade, but it stacks with spread and commission to move the final cent.