What it is and when to use it
This calculator performs linear interpolation (often called a "lerp") between two values, segment A and segment B, using a blend weight between 0 and 1. A weight of 0 returns segment A exactly, a weight of 1 returns segment B exactly, and anything in between returns a proportional mix. It also reports a step increment for breaking the A-to-B span into equal-sized moves, and it clamps the blended result to a minimum and maximum bound so the output never leaves an allowed range.
Use it for animation and transition planning (blending between two keyframe values), gradual ramps such as pay scales or pricing tiers, mixing two forecast or budget scenarios by confidence weight, or any piecewise plan that moves from a starting value to a target value in controlled steps while staying within safe bounds. The clamp inputs are especially useful when the blend weight might be pushed outside its intended range or when downstream values must never exceed a hard limit.
Blend = A × (1 − w) + B × w
Worked example
With A = 18, B = 42, blend weight 0.6, 6 steps, and clamp bounds 10 to 50: Blend = 18 × (1 − 0.6) + 42 × 0.6 = 18 × 0.4 + 42 × 0.6 = 7.2 + 25.2 = 32.4. Step increment = (42 − 18) / 6 = 24 / 6 = 4.00, meaning each of the 6 steps from A to B moves the value by 4. Since 32.4 already falls inside the 10-50 clamp range, the clamped value stays at 32.4 and the delta from A is 32.4 − 18 = +14.40 — matching the calculator's default "Blend Plan" (stable, within range) result.
Common mistakes and how to interpret the result
- Entering a blend weight outside the 0-1 range. Weights are meant to represent a percentage of the way from A to B; the calculator rejects values below 0 or above 1 since they would represent extrapolation beyond the two segments rather than a blend between them.
- Confusing the step increment with the blended value. The step increment describes how big each move is if you split the A-to-B distance into equal pieces; it does not depend on the blend weight at all, only on the number of steps chosen.
- Setting a clamp range that excludes the natural blend result. If your clamp bounds are narrower than where the blended value would naturally fall, the calculator flags "Outside Clamp" and reports the bounded value — check whether the clamp or the blend weight needs adjusting.
- Forgetting the clamp only affects the final blended value, not the step increment. Steps are calculated directly from A and B, so a tight clamp does not change how large each individual step is.