High-Low Method Calculator — Fixed & Variable Cost Split
Enter the highest and lowest activity levels and their corresponding total costs to split a mixed cost into its fixed component and variable rate per unit — instantly, using the classic high-low method from management accounting.
Portion of cost that changes with each additional unit of activity
- 1
Cost range
50,000 − 30,000 = 20,000 - 2
Activity range
10,000 − 4,000 = 6,000 - 3
Variable cost per unit
20,000 ÷ 6,000 = 3.3333The slope of the line joining the high and low data points.
How does this calculator work?
The high-low method splits a mixed cost into fixed and variable parts from just two observations. Variable rate = (High Cost − Low Cost) ÷ (High Units − Low Units); Fixed cost = High Cost − Rate × High Units. Then Total Cost = Fixed Cost + Rate × Units at any activity level — quick to apply but sensitive to outliers.
Formula
How this is calculated
The high-low method is a quick cost-accounting technique for decomposing a semi-variable (mixed) cost into its fixed and variable components using only two data points — the period with the highest activity level and the period with the lowest. The variable cost per unit is the slope of the straight line joining those two extremes: (High Cost − Low Cost) ÷ (High Units − Low Units). The fixed cost component is then back-calculated by subtracting the variable portion from total cost at either point: Fixed Cost = High Cost − (Rate × High Units).
The main strength of the method is simplicity — it requires only basic arithmetic and two observations. The key limitation is that those two extreme points may not be representative; if either period is an outlier caused by a plant shutdown, a seasonal spike or a one-off expense, the split will be distorted. A least-squares regression over all available periods gives a more robust estimate when multiple data points are available.
Once separated, you can forecast total cost at any planned activity level with: Total Cost = Fixed Cost + (Variable Rate × Units). Keep in mind the formula is only reliable within the observed activity range; extrapolating far beyond it is risky if the linear relationship does not hold at all volumes.
Frequently asked questions
Select the period with the highest activity level (units produced, machine hours, etc.) as the high point, and the period with the lowest activity level as the low point. Do not use the highest-cost and lowest-cost periods — those are not necessarily the same periods as the highest/lowest activity, and mixing them up gives the wrong slope.
Yes — if the data is noisy or the two points are atypical, the back-calculated fixed cost can come out negative, which is economically impossible. A negative result signals that one or both observations are outliers, the relationship is not linear, or you have selected the wrong high/low periods.
It lets managers forecast total cost at any planned activity level using Total Cost = Fixed Cost + (Variable Rate × Units). This underpins budgeting, break-even analysis, variance reports and pricing decisions in manufacturing, service and retail businesses.
Also known as
TG we-Calculate Editorial Team. (2026). High-Low Method Calculator — Fixed & Variable Cost Split [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/high-low-method-calculator
TG we-Calculate Editorial Team. "High-Low Method Calculator — Fixed & Variable Cost Split." TG we-Calculate. 2026. https://we-calculate.com/calculator/high-low-method-calculator.
TG we-Calculate Editorial Team, "High-Low Method Calculator — Fixed & Variable Cost Split," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/high-low-method-calculator
@misc{wecalculate_high_low_method_calculator, title = {High-Low Method Calculator — Fixed & Variable Cost Split}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/high-low-method-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?