Smash Bros Knockback Calculator

🎮 Smash Bros Knockback Calculator

Estimate Smash knockback from percent, damage, target weight, knockback growth, base knockback, stale move scaling, rage, launch angle, DI choice, launch speed, and distance to the KO line.

🧭Knockback Presets
Formula note: the calculator uses the Melee-onward knockback structure: percent-after-hit, damage, weight, KBG divided by 100, BKB, then ratio modifiers. Ultimate rage is modeled from 35% to 150% with a 1.10x cap. Smash 4 uses the same rage range with a 1.15x cap. DI is an angle estimate, not an exact game-state simulator.
KBG/100
Knockback growth multiplier in the formula
BKB
Base knockback added after scaling
200/(w+100)
Weight factor for Melee onward
35-150%
Rage percent window in Smash 4 and Ultimate
KB x 0.03
Initial launch speed estimate
80 KB
Common tumble threshold reference
Knockback Inputs
The formula uses percent after the hit; this field is the pre-hit percent you see before contact.
Use the clean hitbox damage before stale multiplier unless you choose direct damage mode.
1.000 means neutral. Lower values reduce displayed damage and knockback damage contribution.
Mario is 98 in Ultimate; Bowser is 135. Enable weight-independent if the move ignores normal weight.
Ultimate and Smash 4 rage start at 35% and cap at 150% attacker percent.
0 is horizontal right, 90 is straight up, 361 is usually treated as a Sakurai angle outside this simplified model.
Ultimate and Smash 4 DI max is commonly estimated near 9.74 degrees.
Use horizontal or vertical blast-line distance from the current position.
Use for crouch, launch-rate rules, stage scripts, armor resistance, or custom lab modifiers.
SmashWiki lists about 186 KB as a center Final Destination no-DI reference for a Sakurai angle.
Knockback Estimate
Total Knockback
0 KB
after rage and ratios
Launch Speed
0.00
initial units per frame
DI Angle
0 deg
estimated launch direction
KO Distance Check
Check
against entered blast-line distance
Formula Breakdown
Enter move and stage context to estimate knockback.
📋Distance And Percent Tables
Percent sweep for the current move
Victim percent before hitPost-hit percentKnockbackLaunch speedDistance signal
Run the calculator to fill this table.
The sweep keeps move stats, rage, stale multiplier, weight, angle, and distance model unchanged while varying victim percent.
Weight comparison for the current hit
Target typeWeight valueEstimated KBInitial speedSurvival note
Run the calculator to fill this table.
Weight values are examples drawn from common Ultimate character bands. Use exact character data for final lab work.
🔬Formula References
Knockback variables used by this calculator
VariableMeaningCalculator fieldHandling note
pTarget percent after the hitVictim percent + stale-adjusted damageStamina Mode is not modeled; use normal percent battles.
dDamage contributionMove damage with stale/fresh adjustmentUltimate and Smash 4 use only part of stale/fresh for knockback damage contribution.
wTarget weightTarget weight valueWeight-independent moves set this to 100.
sKBG divided by 100Knockback growthA KBG of 110 is entered as 110 and converted to 1.10 internally.
bBase knockbackBKBAdded after the percent, damage, weight, and KBG portion.
rRatio modifiersRage, launch rate, extra ratioRage, launch rate, crouch-like adjustments, and custom modifiers multiply final KB.
Common knockback and angle reference values
ReferenceValueUse in calculatorPractical note
Tumble thresholdAbout 80 KBStatus signalBelow this, the hit is usually combo or positioning oriented.
Side KO referenceAbout 172 to 205 KBManual KO thresholdDI and position can swing this heavily.
No-DI center referenceAbout 186 KBDefault thresholdA SmashWiki reference for center Final Destination with a Sakurai angle.
Launch speedKB x 0.03Speed result cardMomentum then decays by about 0.051 per frame.
Ultimate DI capAbout 9.74 degDI estimateApplies as an angle estimate in this simplified tool.
Sakurai angle361 inputEnter 0, 32, or 45 manuallyThis calculator does not auto-resolve the special 361 angle.
Ultimate weight examples for quick testing
Character or bandWeightUse caseKnockback expectation
Pichu62Very light targetLaunches much farther from the same hit.
Fox77Light fast faller checkUseful for side-KO and combo tests.
Mario98Middleweight defaultGood neutral comparison target.
Samus or Terry band108Heavyweight comparisonNeeds more percent or stronger KBG.
Ganondorf118Super-heavy planningOften survives side hits longer.
Bowser135Heaviest common benchmarkLowest KB from normal weight scaling.
Rage, staling, DI, and distance handling
MechanicModeled valueInput fieldLimitation
Ultimate rage1.00x to 1.10xAttacker percentStarts at 35% and caps at 150%.
Smash 4 rage1.00x to 1.15xGame mode and attacker percentModeled as a linear planning curve.
Stale damageDamage x stale multiplierStale selectorMove queue history is entered as one multiplier.
Knockback stale term30% of stale differenceDirect damage toggleMatches the common Smash 4 and Ultimate planning formula.
DIAngle shift estimateDI selectorDoes not simulate hitlag, position, walls, or recovery.
KO line distanceDistance along chosen axisKO distance modelSimple distance score, not exact blast-zone physics.
💡Calculation Tips
Percent check: the formula uses post-hit victim percent, so stale damage changes both the displayed percent gain and the knockback calculation.
Weight check: changing only target weight is the fastest way to compare whether a move is a true KO tool or mainly a light-character check.
Rage check: Ultimate rage is smaller than Smash 4 rage. Swap the mode before comparing old clips or lab notes.
DI check: DI shifts the launch angle estimate. It can turn a side KO into a corner survival even when total KB is unchanged.
Distance check: set the KO distance to the nearest blast line from the victim's position, not the full stage width.
Data check: use exact hitbox damage, KBG, BKB, and angle from a frame-data source when testing one specific move.

The physics in Smash Bros is governed by different rules then what we think is logical. A heavy attack could feel like you landed it well, but it’s based off vector and mass rather than your intention. Knowing how these work versus just guessing are what makes you good.

Since the days of Melee, knockback works on a very simple formula that isn’t based on feeling, but instead on data points. Not all knockback scale linearly. What will launch a light character might not have same effect on heavy character. In fact it’s largely dependent upon weight. This is where the calculator come into play.

Why Math Is Important In Smash Bros

By taking into account the base knockback value as well as weight of the target, the calculator figures out if it was deadly or a combo set-up. Without math you don’t really know what to expect from your attack.

The Rage mechanic builds up the damage/launch force based on their opponents’ percent. In Smash 4 and Ultimate, this range from thirty-five to one-hundred-fifty percent. A late-game smash hit will not only deal additional damage but also increase the launch force. Before committing to an attack, you need to consider this multiplier. Otherwise, you could of ended up going out of bounds while your opponent recovers.

Reducing damage does not change direction of the launch, which is called directional influence, or DI. While a good steer may transform a horizontal launch into a vertical one and keep you closer to the center of the stage, a bad steer will shoots you right down the blast line. The tool takes that difference in angle into account when estimating where you’ll land. In high-level play, that make a huge difference as it impacts your survival options.

Repeated use of a move also decrease its knockback and damage due to stale move data. While not so noticeable in the heat of battle, over time this can affect combo string. For example, if a forward aerial kills at 80% health, it might just juggle after being used five times in a row. You can tweak stale multipliers via the calculator. It’s easy to get carried away with base stats and forget what went into them; this let you match your expectations with reality.

Each of these hits is also viable depending on geometry of stage as well. How far away is it from the blast line? Is it launching horizontally at edge of the stage or from the middle of it? You can input this into the tool as well and it connects those numbers to real world space, grounding the calculation in actual space where the match is being played. That’s when those variables become a science.

It goes from guesswork to strategic decision making. It becomes about using information instead of gut feeling. And in that moment, before you even land the hit, it’s already determined if it will have an impact or not. That’s what gives one person the advantage more then another in tournament competition.

Smash Bros Knockback Calculator

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