How to Calculate Interest on USDT Futures Margin

To calculate interest earned on USDT futures margin, work out base interest and position-based bonus interest separately, then account for the period each qualified. Multiplying your full balance by the advertised 20% APR works only if that whole amount receives both the base and maximum bonus rates for the entire period.

Calculate Base and Bonus Interest Separately

For MEXC Futures Earn, record the principal and APR applicable to base interest and, separately, to position-based interest. Use the period for which each qualifies.

The public USDT offer shows 5% base APR and a 100-USDT minimum balance. Base interest requires no position after activation. Position value determines the additional APR; it is not the principal earning interest.

Your personalized APR and principal limits can differ from advertised maximums. Use the actual account figures, including separate base and bonus caps.

When both components qualify for the same period at constant amounts and rates:

Estimated interest = [(base principal × base APR) + (bonus principal × additional APR)] × days ÷ 365.

If qualifying periods differ, calculate each component for its own period and add the results. Here, “additional APR” means the position bonus alone. For the maximum advertised tier, 5% base plus 15% additional APR equals 20% total.

Reproduce an Estimate in MEXC’s Calculator

On the MEXC Futures Earn page, select the calculator icon beside “What is Futures Earn?” In “Calculate Interest,” choose USDT and enter:

• Futures Account Principal: 10,000 USDT.
• Futures Position Value: 50,000 USDT.
• Interest Accrual Period: 1 day using the Custom field.

The public calculator returns approximately 2.74 USDT. The 50,000-USDT qualifying position unlocks an additional 5% APR in this scenario:

Base interest: 10,000 × 5% ÷ 365 ≈ 1.37 USDT.

Position bonus: 10,000 × 5% ÷ 365 ≈ 1.37 USDT.

Keeping those inputs and changing the period to 30 days produces approximately 82.19 USDT. Both estimates assume continued qualification; the public calculator does not replace your account’s personalized quote.

Round the final total: multiplying the rounded daily figure, 2.74, by 30 would give 82.20 USDT.

Apply Each Principal Cap Before Adding the Interest

For a hypothetical MEXC Futures Earn account, suppose 10,000 USDT qualifies for 5% base APR, but only 2,000 USDT qualifies for the maximum additional 15% APR. Assume full-day eligibility. These amounts illustrate cap effects; replace them with your account’s limits. The bonus covers part of the same 10,000-USDT balance.

The annualized interest amounts are 500 USDT from the base rate and 300 USDT from the bonus. Dividing their sum by the 10,000-USDT balance gives an 8% blended simple APR, despite qualification for the maximum bonus tier.

For a fixed bonus-principal cap, increasing position value cannot make the amount above that cap earn bonus interest.

Recalculate When the Eligible Balance Changes

MEXC Futures Earn accrues interest hourly. For a simple hourly estimate, divide annual interest by 365 × 24 and add the qualifying hours.

Suppose the recorded eligible principal is 10,000 USDT for 12 hours and 5,000 USDT for another 12 hours, all at a constant 5% base APR. Assume there is no position bonus and neither balance hits a cap.

Estimated interest = [(10,000 × 12) + (5,000 × 12)] × 5% ÷ (365 × 24) ≈ 1.03 USDT.

Using only the closing 5,000-USDT balance would give about 0.68 USDT. Reconcile the estimate against the principal and applicable rates recorded for the calculation period; platform measurement and rounding govern settlement.

For activation and balance qualification, see how to earn interest on USDT while trading futures.

Risk Warning

Interest estimates exclude trading fees, funding payments, liability interest and trading losses. Larger positions used to qualify for bonus tiers increase trading exposure; their losses can exceed the interest earned.