Our billing system provides precise, per-second billing accuracy while using hourly intervals for reporting and API queries. This guide explains how we calculate costs with second-level precision and what this means for your billing.
How Per-Second Billing Works
Precise Time Tracking
Start/Stop Times: We track the exact second when resources start and stop
Duration Calculation: Billing duration is calculated to the precise second
Fractional Hours: Costs are calculated using fractional hours (e.g., 4.504166667 hours = 4 hours 30 minutes 15 seconds)
Example: GPUaaS Pool Usage
Start Time: 2025-10-13 08:30:00
End Time: 2025-10-13 13:00:00
Duration: 4 hours 30 minutes
Billed As: 4.5 hours
📊 Understanding Fractional Hours
Common Fractional Hour Values
Duration | Fractional Hours | What You'll See in Billing |
|---|---|---|
30 minutes | 0.5 hours |
|
1 hour 15 minutes | 1.25 hours |
|
2 hours 45 minutes | 2.75 hours |
|
4 hours 30 minutes | 4.5 hours |
|
8 hours 20 minutes | 8.33 hours |
|
Precision Examples
{
"pool_hours": 4.583333, // 4 hours 35 minutes
"interval_cost": "38.25", // $8.34/hour × 4.583333 hours
"subscription_rate": "8.34"
}
Cost Calculation Examples
Basic Calculation
Hourly Rate: $8.34/hour
Usage Time: 2 hours 30 minutes (2.5 hours)
Cost: $8.34 × 2.5 = $20.85
Real-World Scenarios
Scenario 1: Short Usage
GPU Pool Usage: 45 minutes
Calculation: $8.34 × 0.75 hours = $6.26
You Pay: $6.26 (not a full hour)
Scenario 2: Partial Day
Instance Running: 6 hours 20 minutes
Calculation: $2.50 × 6.33 hours = $15.83
You Pay: $15.83
Scenario 3: Month-End Cleanup
Storage Mounted: 28 days 14 hours 30 minutes
Daily Breakdown:
- 28 full days: 28 × 24 = 672 hours
- Partial day: 14.5 hours
- Total: 686.5 hours
Cost: $0.10 × 686.5 = $68.65
📈 Billing Intervals vs. Billing Precision
Important Distinction
Aspect | How It Works |
|---|---|
Billing Precision | ✅ Per-second accuracy - costs calculated to the exact second |
API Query Intervals | ⏰ Hourly minimum* - can query by hour, day, week, month |
Cost Calculation | 💰 Fractional hours - uses decimals for precise billing |
*Hourly endpoints will be available from our 2.1 release.
What This Means
Users are billed precisely for the time used
API reports in hourly intervals for practical querying
No "rounding up" to full hours - users pay for exact usage
🔍 Reading Your Billing Data
API Response Format
{
"2025-10-13": {
"interval_hours": 4.583333, // 4 hours 35 minutes
"interval_cost": "38.25", // Exact cost for 4.583333 hours
"from": "2025-10-13T08:25:00Z", // Precise start time
"to": "2025-10-13T13:00:00Z", // Precise end time
"subscription_rate": {
"price": "8.34" // Hourly rate
}
}
}
Key Fields to Understand
interval_hours: Exact usage time as fractional hoursinterval_cost: Precise cost based on exact usagefrom/to: Exact start and end timestampsprice: Hourly rate used for calculation
Practical Examples
Development Workflow
1. Start GPU instance: 09:15:30
2. Run training job: 2 hours 23 minutes
3. Stop instance: 11:38:30
4. Billed for: 2.383 hours (not 3 full hours)
5. Cost: $8.34 × 2.383 = $19.87
Testing Environment
1. Deploy test environment: 14:45:00
2. Run tests: 47 minutes
3. Cleanup: 15:32:00
4. Billed for: 0.783 hours
5. Cost: $5.00 × 0.783 = $3.92
📋 Frequently Asked Questions
Q: Why do I see decimal hours instead of minutes?
A: Our billing system uses industry-standard fractional hours (4.5 hours = 4 hours 30 minutes) for precise calculations while maintaining compatibility with hourly pricing models.
Q: How precise is the time tracking?
A: We track resource assignment to the second, then calculate costs using fractional hours for maximum accuracy.
Q: Can I query billing data by minute?
A: API queries are as granular as hourly, but the costs within each hour are calculated with per-minute precision.
Q: Why might I see values like 71.999999 hours?
A: This represents floating-point precision in calculations. 71.999999 hours is effectively 72 hours (3 days) in billing terms.