The most powerful free weighted average time calculator for project managers. Compute weighted durations, delivery estimates, response time metrics, and schedule-weighted deadlines with live interactive charts.
Enter tasks to compute weighted average time.
A weighted average time assigns different importance to each duration based on how frequently it occurs or how significant the task is. If a task takes 2 hours 80% of the time and 10 hours 20% of the time, the weighted average is 3.6 hours — not the simple average of 6 hours.
Simple averaging treats all time measurements equally regardless of frequency. If 95% of tickets resolve in 5 min and 5% take 120 min, the simple average is 62.5 min — but the weighted average is 10.75 min. The time calculator prevents this scheduling error.
Type each duration into the Value column — hours, minutes, days, or any time unit you want to average across your tasks or deliveries.
Enter the weight for each time value. In time analysis, weights are typically occurrence counts, task frequencies, or importance scores.
The calculator computes your result instantly. See the weighted mean duration, sum of products, and all interactive charts update in real time.
The weighted average time formula: multiply each duration by its frequency, sum those products, then divide by the total frequency count. This produces the true weighted time.
Enter each task duration alongside its occurrence count. Example: Quick tasks 15 min (50x), Medium tasks 45 min (30x), Complex tasks 120 min (10x).
Quick: 15 × 50 = 750, Medium: 45 × 30 = 1350, Complex: 120 × 10 = 1200.
750 + 1350 + 1200 = 3300. This is the numerator in the weighted average formula.
50 + 30 + 10 = 90. This is the denominator.
3300 ÷ 90 = 36.67 min. The true average task duration, not 60 min (simple average).
Averaging task times without weighting by frequency produces misleading estimates. The time calculator weights correctly.
Dividing total time by task type count instead of total occurrences is wrong. Always divide by the sum of frequencies.
Swapping the duration with frequency count produces a wrong weighted average. The labeled columns prevent this.
Multiply each duration by its frequency. Sum products. Sum frequencies. Divide. The calculator automates this.
Compute true average task durations. Edit durations and frequencies below.
The weighted average time is 36.67 min, not 60 min (simple average). Quick tasks dominate because they occur most frequently (50 times).
Calculate weighted average delivery time across shipping methods.
The weighted average delivery time is 3.8 days, reflecting the blended shipping time weighted by order volume.
Calculate true weighted average task duration across project activities, weighting by occurrence frequency.
Compute weighted average response times across support tiers, weighting by ticket volume.
Calculate weighted average delivery times across shipping methods, weighting by order volume.
Compute weighted average cycle times across manufacturing processes where weights represent batch sizes.
Frequencies must be positive. The time calculator requires positive weights (frequencies or importance scores). A weight of zero means the task is excluded entirely.
Equal frequencies = simple average. If every task has the same frequency, the weighted average time equals the simple average. Unequal frequencies are where weighted time averages shine.
Weighted time stays between shortest and longest. No matter how you distribute frequencies, the weighted average time will always be between the shortest and longest individual durations.
Higher-frequency tasks dominate the average. The more frequently a task occurs, the more the weighted time is pulled toward that task duration. This is the key insight of weighted average time analysis.
Fifteen purpose-built weighted average calculators — each tailored to a specific domain with unique inputs, outputs, and interactive visualizations.
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Compute your grade point average across multiple courses.
Apply a weighted moving average to time-series data.
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Inventory valuation, unit costs, and supplier comparison with quantity weighting.
Blended pay rates, overtime costs, and department salary analysis by headcount.
Weighted durations, delivery estimates, and PERT scheduling by task frequency.
Weighted mean, variance, standard deviation, and coefficient of variation analysis.
Compute the weighted arithmetic mean from data values with different frequencies or importance weights.
Compute composite scores from weighted categories for rubrics, tests, and evaluations with letter grades.
Calculate VWAP, average purchase price, and procurement costs weighted by quantity or volume.
Compute true portfolio returns by weighting each asset's performance by its dollar allocation.
Combine ratings from multiple review sources weighted by review count or credibility.
Compute blended interest rates across loans, savings, and credit lines weighted by balance.
Analyze blended profit margins across products, services, and segments weighted by revenue.
A weighted average time calculates the mean duration across multiple tasks where each is weighted by its frequency or importance. Quick tasks happening 50 times at 15 min and complex tasks 10 times at 120 min gives a weighted average of 36.67 min — not 67.5.
Multiply each method time by its order count, sum all products, then divide by total orders. Express (2 days × 100) + Standard (5 days × 300) + Economy (10 days × 50) = 2200 ÷ 450 = 4.89 days.
Simple average treats all response categories equally regardless of volume. If 90% of tickets resolve in 5 min and 10% take 60 min, simple average shows 32.5 min but weighted average is 10.5 min.
Yes! PERT uses a weighted average: (Optimistic + 4×Most_Likely + Pessimistic) / 6. Enter your three estimates with weights 1, 4, and 1 to get the PERT expected duration.
It gives realistic task duration estimates by accounting for how often different scenarios occur, preventing over- or under-estimating and leading to more accurate project schedules.