How to use this calculator
- Enter current inventory.
- Add average daily sales and supplier lead time.
- Enter safety stock for the analysis period.
- Click Calculate to review result, status, health score, and recommendation.
#1048 · E-commerce Tool
eBay Inventory Calculator
Use this eBay Inventory Calculator to decide when to reorder and avoid stockouts. It uses current stock, daily sales, supplier lead time, and safety stock to estimate days remaining, reorder point, inventory risk, and 30-day forecast.
Calculator
E-commerce decision inputsunits
units/day
days
units
Ad space
What the result means
Inventory is healthier when days left exceed lead time plus safety stock without tying up too much cash in slow-moving units.
Days left = current inventory ÷ daily sales. Reorder point = daily sales × lead time + safety stock.
Seasonality, promotions, and supplier delays can change sales velocity quickly, so update inputs after major traffic changes.
Example calculation
With 160 units, 6 daily sales, 14-day lead time, and 30 safety units, days left are 26.7 and reorder point is 114 units.
Tips for better results
- Reorder before inventory falls below the reorder point.
- Increase safety stock for seasonal or unreliable suppliers.
- Reduce reorder quantity for slow-moving SKUs.
- Monitor sell-through after promotions.
FAQ
When should I reorder inventory for eBay?
Reorder when current inventory approaches daily sales multiplied by supplier lead time plus safety stock.
How do I calculate eBay days until stockout?
Divide current inventory units by average daily sales to estimate how many selling days remain.
What is a good inventory turnover for eBay sellers?
Good turnover depends on category, but faster turnover with low stockout risk is usually healthier than slow-moving excess stock.
How much safety stock should I keep for eBay inventory?
Use more safety stock when supplier lead time is long, demand is seasonal, or stockouts are costly.
How do I avoid running out of stock on eBay?
Track daily sales velocity, lead time, safety stock, and reorder before inventory drops below the reorder point.
Related calculators
Decision module
| Metric | Meaning |
|---|---|
| Days left | Estimated selling days before stockout. |
| Reorder point | Inventory level where reorder should happen. |
| Stockout risk | Compares days left with supplier lead time. |
| Inventory control | Supports reorder timing decisions. |
Browse more calculators
Category hubsFinanceInvestment, savings, debt, retirement, and money planning.View all
MarketingAds, campaign profit, conversion, ROAS, and ROI tools.View all
Social MediaYouTube, Instagram, followers, engagement, and creator metrics.View all
ProductivityTime, focus, task, schedule, habit, and capacity tools.View all
BusinessProfit, margin, unit economics, operations, and cash flow.View all
E-commerceStore revenue, pricing, order value, conversion, and profit.View all
Real EstateMortgage, rent, property return, affordability, and cash flow.View all
StartupRunway, CAC, LTV, burn rate, growth, and SaaS metrics.View all
TaxIncome tax, deduction, paycheck, and estimated tax planning.View all
SalaryPaycheck, wage, bonus, overtime, commission, and net pay.View all
EducationStudy planning, grades, score tracking, and learning calculators.View all
HealthFitness, nutrition, body metrics, and wellness estimates.View all
LifestyleDaily life, planning, personal decisions, and simple estimates.View all
TravelTrip cost, budget, distance, itinerary, and travel planning tools.View all