Size every trade.
Protect every account.
The only calculator that knows your prop firm's rules. Gold and indices calculated correctly for your broker. Two taps to your lot size.
Free trial. 3 days monthly, 7 days annual.
Trusted by traders on
How it works
Select your firm
FTMO, FundedNext, FundingPips — your daily loss limit loads automatically.
01Enter your trade
Balance, risk %, instrument, stop loss. Pre-filled from your last session.
02Get your lot size
Calculated in real time. Copy it. Trade it.
03Also built in
Voice input
Say your trade out loud. Instrument, entry, stop loss, risk. Fields fill automatically.
Works offline
No live prices needed. Opens ready to calculate. No loading, no waiting.
Every calculation. Shareable in one tap.
Branded trade card showing your position, risk, lot size and firm. Share directly to X in one tap.
The app UX is great and it took 2 taps to get my lot size, switch between accounts and sizes — for me that trades multiple accounts, super easy. Compared to the web calculator I was using, it takes ages to scroll to find the pair I'm trading, I still have to manually type in my account size every time which was a pain. Not to talk of the ads that I had to dismiss like 2 or 3 of them. This actually just saved me from missing my entry.
Start free. Cancel anytime.
Full access during your trial.
Frequently asked questions
After setup, just enter your stop loss and tap Calculate. Your firm, balance, and risk % are already pre-filled from your last session. PropSize applies FTMO's 5% daily loss limit automatically. Your lot size is ready in two taps.
Gold requires a specific contract size that varies by broker — most web calculators get this wrong. PropSize walks you through finding the exact contract size in your MT5 platform, saves it, and uses it for every calculation after that. You only do this once.
Yes. FTMO's 5% daily loss limit, FundedNext's 5%, and FundingPips' 4% are all pre-loaded. An amber warning appears when your position approaches 80% of the limit — giving you time to size down before it becomes a violation.
Switch between firms and account sizes in seconds. PropSize pre-fills from your last session — no manual setup every time you open the app.
Yes. PropSize works fully offline. No live price feeds, no loading screens. It opens ready to calculate — useful when you're mid-session and need a number fast.
For forex pairs the math is exact. For gold (XAUUSD) and indices, PropSize guides you to find your broker's exact contract size in MT5, saves it, and uses it for every calculation. For cross pairs, approximate FX rates are used, accurate to within 1-2%.
No free tier — PropSize uses a free trial model instead. Monthly plan gets 3 days, annual gets 7 days. Full access during the trial. Card required upfront.
Start sizing trades the right way.
Free 7-day trial. Cancel anytime.
"I built PropSize after nearly blowing an FTMO challenge on a gold lot size mistake. I was using a web calculator that didn't know my daily loss limit, didn't handle XAUUSD contract sizes, and showed me ads while I was trying to enter a trade. PropSize fixes all of that."— Justice, PropSize developer · @justice_note