Calculator
Formula Used
Energy per monitor (kWh/day) = (Watts ÷ 1000) × Hours/day
Energy cost = kWh/day × Electricity rate
Labor cost = (Minutes/day ÷ 60) × Labor rate
Data daily = Monthly data plan ÷ 30.44
Maintenance daily = Monthly maintenance ÷ 30.44
Calibration daily = Calibration cost ÷ Interval days
Base cost per monitor = Energy + Labor + Data + Maintenance + Calibration + Rental + Consumables
Subtotal per day = Base cost per monitor × Number of monitors
Overhead = Subtotal × (Overhead % ÷ 100)
Grand total per day = Subtotal + Overhead + Tax
How to Use This Calculator
- Enter the number of monitors and operating hours per day.
- Fill in power draw and local electricity rate.
- Add rental, consumables, labor time, and labor rate.
- Provide monthly data and maintenance costs for prorating.
- Set calibration cost and the calibration interval in days.
- Optional: add overhead and tax for your billing structure.
- Press Calculate Cost to view totals and breakdown.
- Use Download CSV or Download PDF for reports.
Example Data Table
Sample inputs and outputs help validate your setup and expectations.
| Input | Value |
|---|---|
| Monitors | 2 |
| Hours/day | 24 |
| Power (W) | 8 |
| Electricity rate ($/kWh) | 0.2200 |
| Rental ($/day each) | $15.00 |
| Consumables ($/day each) | $1.50 |
| Labor (min/day each) | 10 |
| Labor rate ($/hour) | $12.00 |
| Data plan ($/month each) | $8.00 |
| Calibration ($ per event) | $40.00 |
| Calibration interval (days) | 30 |
| Maintenance ($/month each) | $5.00 |
| Overhead (%) | 10.0% |
| Project days | 45 |
Cost Drivers That Matter Most
Daily air monitoring costs on active construction sites typically come from a few repeatable buckets: energy, labor, connectivity, service, and materials. Small monitors often draw single‑digit watts, so electricity is usually modest, but it becomes noticeable when devices run 24 hours and tariffs rise. Labor can dominate when technicians perform frequent checks, move units for changing work fronts, or validate alarms against site conditions. This calculator separates each cost driver so you can see where your budget is truly going and what to optimize first.
Power and Operating Time Estimation
Power cost uses wattage converted to kWh, multiplied by your local energy rate. For example, an 8 W monitor running 24 hours uses about 0.192 kWh/day. At $0.22 per kWh, that is roughly $0.04 per day per device. If you switch to a higher‑draw unit, or reduce operating hours to a single shift, the energy line updates instantly and helps you compare monitoring strategies.
Labor Time, Response, and Documentation
Many projects underestimate labor. Even 10 minutes per monitor per day adds up across multiple units. Include time for bump tests, reviewing dashboards, relocating monitors, and recording compliance notes. If your workflow improves and you reduce checks from 15 minutes to 7 minutes, the calculator will show the daily savings and the impact across a full project duration. This is especially useful when building rate sheets for subcontractor or client billing.
Calibration, Maintenance, and Consumables
Calibration is prorated by interval days, turning a periodic service event into a predictable daily cost. Shorter intervals increase daily cost but may reduce risk and downtime. Maintenance is prorated from a monthly allowance for parts and service coverage. Consumables capture small recurring items such as inlet filters, wipes, tubing, and protective housings. Together, these lines make the long‑run “true cost” visible, not just the rental or purchase price.
Example Data for a Typical Deployment
Example scenario: 2 monitors, running 24 hours/day, at $0.22 per kWh, with $15.00 rental per day each and 10 minutes of daily checks. The estimated total is $44.67 per day, or $2,009.97 for 45 days.
| Metric | Value |
|---|---|
| kWh/day per monitor | 0.1920 |
| Energy cost/day per monitor | $0.04 |
| Labor cost/day per monitor | $2.00 |
| Daily total (all monitors) | $44.67 |
How many monitors should I budget for?
Use your monitoring plan and coverage rules, then enter that count here. If you are unsure, model low, expected, and high counts to see budget ranges.
Does this include equipment purchase depreciation?
Not directly. If you own monitors, you can approximate depreciation by entering a daily “rental/lease” amount that reflects your desired recovery rate and lifecycle.
Why does the calculator divide monthly costs by 30.44?
30.44 is the average days per month across a year. It converts monthly plans and allowances into a realistic daily cost for consistent comparisons.
How should I set calibration interval days?
Use your internal QA plan, contract requirements, and sensor type. Shorter intervals increase daily cost but can reduce drift risk and unexpected downtime.
Can I estimate a single shift instead of 24-hour monitoring?
Yes. Change hours per day to match your monitoring window. The energy cost will scale with time, while rental and some service costs may remain daily.
What should I include in consumables?
Include small recurring items used to keep readings reliable: filters, wipes, inlet caps, tubing, protective enclosures, and replacement sample heads.
How do I share results with stakeholders?
After calculating, download CSV for spreadsheets or PDF for quick reports. Attach exports to daily logs or cost justifications for approvals.