Pattern Day Trader (PDT) Calculator
Estimate your PDT risk, required equity, and buying power using a simplified FINRA-style framework.
Educational calculator only. Broker-specific rules and real-time account details may differ.
What Is the PDT Rule?
PDT stands for Pattern Day Trader. Under U.S. FINRA rules, a margin account can be labeled a pattern day trader if it executes 4 or more day trades in 5 business days, and those day trades are more than 6% of total trading activity in that same period.
Once an account is classified as PDT, it generally needs at least $25,000 in equity to continue day trading without restriction. If equity falls below that threshold, your broker may limit new day trades until funds are added or positions are adjusted.
How This PDT Calculator Works
1) Equity check
The first thing the tool checks is your account equity against the $25,000 threshold. If equity is below $25,000, the calculator flags how much additional capital would be needed to meet the typical minimum.
2) Rolling 5-day day trade count
Next, it projects your day trade total after today's planned activity. This helps you estimate whether you are likely to cross the common 3-day-trade limit used by many traders trying to avoid a PDT designation in small accounts.
3) Simplified buying power estimate
The calculator uses a common approximation:
- Maintenance Margin Excess = Equity − Maintenance Margin Requirement
- Day-Trading Buying Power (DTBP) ≈ 4 × Maintenance Margin Excess
- Overnight Buying Power ≈ 2 × Maintenance Margin Excess
Real broker calculations can vary, but this provides a practical planning baseline.
Why Traders Use a PDT Calculator
- To avoid accidental rule violations in active weeks.
- To estimate whether account size supports a day-trading strategy.
- To compare strategy pace (trade frequency) with account constraints.
- To decide whether to reduce trade count or add capital.
Example Scenarios
Scenario A: Smaller account under $25k
Suppose your equity is $18,500 and you already have 3 day trades in the last 5 business days. Planning two more day trades likely places the account in a restricted position. The calculator will highlight both the projected count and your equity shortfall.
Scenario B: Account above $25k
If your equity is $42,000 and your maintenance requirement is $12,000, your maintenance excess is $30,000. A simplified DTBP estimate would be $120,000. You may still qualify as PDT based on frequency, but with sufficient equity, the practical impact is usually reduced.
Ways to Reduce PDT Risk
- Track day trades daily and keep a 5-business-day log.
- Use fewer intraday round trips in low-conviction setups.
- Consider swing trading more positions overnight when appropriate.
- Build a pre-trade checklist that includes "PDT impact."
- Confirm your broker's exact policy; implementation details differ.
Frequently Asked Questions
What counts as a day trade?
A day trade is generally an opening and closing transaction in the same security on the same trading day in a margin account (for example, buy then sell, or short then cover).
Does the PDT rule apply to cash accounts?
PDT is primarily a margin-account rule. Cash accounts have different constraints, including settlement rules, which can still limit trading frequency.
Can this calculator replace broker statements?
No. This tool is a planning aid. Always defer to your broker's official calculations, notices, and compliance rules.
Final Note
A good PDT workflow combines position sizing, trade journaling, and rule awareness. Use this calculator before market open to sanity-check your planned activity and keep your strategy aligned with account limits.