M-Ratio Calculator: Tournament Stack Survival

The M-Ratio measures tournament stack health—how many orbits you can survive before being blinded away. Our calculator reveals your M-Zone, when to shift from standard play to push/fold, and how Dan Harrington's revolutionary concept guides tournament survival.

What Is M-Ratio?

M-Ratio (or just "M") is your stack divided by the cost of one orbit (small blind + big blind + antes). An M of 20 means you can survive 20 orbits playing zero hands. Lower M requires more aggression; higher M allows patient play. This concept was popularized by Dan Harrington.

Quick Answer: M = Stack ÷ (SB + BB + Antes). Measures orbits of survival. Green Zone M>20: Full strategy. Yellow Zone M 10-20: Tighten, add aggression. Orange Zone M 6-10: Push/fold approaching. Red Zone M 1-5: Push/fold mode. Dead Zone M<1: Almost dead. Guides tournament aggression levels.

How to Use Our Calculator

Use the M-Ratio Calculator →

Calculate your tournament M-Ratio.

Step-by-Step Instructions

1. Enter Your Stack: Current chip count

2. Input Blinds: Small and big blind

3. Add Antes: If applicable

4. View M-Ratio: Your current M

5. Check Zone: Strategy recommendation

Input Fields Explained

Field	Description	Example
Stack	Your chips	15,000
Small Blind	SB amount	200
Big Blind	BB amount	400
Antes	Per player ante	50×9 = 450
M-Ratio	Stack ÷ Orbit Cost	14.3

The M-Zones

Green Zone (M > 20)

Green Zone strategy:

M > 20
Full poker freedom
All strategies available

What you can do:
Limp, raise, 3-bet
Play drawing hands
Set mine profitably
Make moves post-flop
No survival pressure

Example:
Stack 50,000
Orbit cost 2,000
M = 25
Play normal poker

Yellow Zone (M 10-20)

Yellow Zone strategy:

M = 10-20
Still flexible but aware
Tighten hand selection
Add preflop aggression

What changes:
Fewer speculative hands
More preflop raising
Less calling
Position more important

Example:
Stack 30,000
Orbit cost 2,000
M = 15
Be selective, be aggressive

Orange Zone (M 6-10)

Orange Zone strategy:

M = 6-10
Approaching push/fold
First-in aggression key
No more limping

What changes:
Shove or fold with many hands
3-betting = shoving
Calling = committing
Simple poker

Example:
Stack 16,000
Orbit cost 2,000
M = 8
Shove with wide range

Red Zone (M 1-5)

Red Zone strategy:

M = 1-5
Push/fold only
Any first-in = shove
Fold equity critical

What changes:
No raising except all-in
Looking for spots to shove
Fold equity > card value
Survival mode

Example:
Stack 8,000
Orbit cost 2,000
M = 4
Shove Ax, Kx, pairs, suited

Dead Zone (M < 1)

Dead Zone reality:

M < 1
Desperately short
Any playable hand = shove
Almost no fold equity

What happens:
You'll be called
Need to win showdown
Take any chance

Example:
Stack 1,500
Orbit cost 2,000
M = 0.75
Shove anything decent

M-Ratio Calculations

Basic Formula

M = Stack ÷ (SB + BB + Antes)

Example 1 (no antes):
Stack: 20,000
SB: 100, BB: 200
Orbit cost: 300
M = 20,000 ÷ 300 = 66.7

Example 2 (with antes):
Stack: 20,000
SB: 200, BB: 400
Antes: 50 × 9 = 450
Orbit cost: 1,050
M = 20,000 ÷ 1,050 = 19

Effective M

Effective M (short-handed):

Standard M assumes full table (9-10)
Adjust for fewer players

Effective M = M × (Players/10)

Example:
Your M = 20
6-handed table
Effective M = 20 × (6/10) = 12

You're more orange than green
Blinds come faster

Strategy by Zone

Green Zone Play

M > 20 strategies:

Open wide from late position
Defend blinds appropriately
3-bet for value and bluff
Play post-flop poker
Set-mine with small pairs
Play suited connectors
No rush, no panic

Yellow Zone Play

M 10-20 strategies:

Tighten opening range
Reduce calling
Increase 3-bet shoving
Avoid marginal spots
Position premium
Start accumulating or stay stable
Avoid big pots with medium hands

Orange Zone Play

M 6-10 strategies:

Shove or fold most spots
Open-shove becomes standard
Don't raise-fold
3-bet = all-in
Look for first-in spots
Any Ace, any pair
Suited broadways
Be first aggressor

Red Zone Play

M 1-5 strategies:

Push/fold charts
Any face card
Any Ace
Any pair
Suited connectors
Looking for double-up
Any fold equity is good
Don't wait for AA

Real-World Examples

Example 1: Green Zone Comfort

Full flexibility:

WSOP Main Event Day 2
Stack: 120,000
Blinds: 400/800/800 ante
9-handed

Orbit cost: 400 + 800 + 7,200 = 8,400
M = 120,000 ÷ 8,400 = 14.3

Yellow Zone—but close to green
Still plenty of play
Selective aggression
Normal poker available

Example 2: Orange Zone Shove

Limited options:

Online tournament
Stack: 18,000
Blinds: 500/1,000/100 ante
9-handed

Orbit cost: 500 + 1,000 + 900 = 2,400
M = 18,000 ÷ 2,400 = 7.5

Orange Zone
First-in with K♠T♦?
Shove! Don't raise-fold
Need fold equity

Example 3: Red Zone Desperation

Must move:

Final table bubble
Stack: 8,000
Blinds: 800/1,600/200 ante
8-handed

Orbit cost: 800 + 1,600 + 1,600 = 4,000
M = 8,000 ÷ 4,000 = 2

Red Zone
Shove with anything playable
7♠6♠ UTG? Maybe
A♣4♦ any position? Yes
No time to wait

Example 4: Dead Zone Prayer

All-in mentality:

Turbo tournament
Stack: 2,500
Blinds: 500/1,000/100 ante
6-handed

Orbit cost: 500 + 1,000 + 600 = 2,100
M = 2,500 ÷ 2,100 = 1.2

Dead Zone
Effective M even worse: 0.7
Shove next playable hand
Q♠8♦? Good enough
Need miracle

Common Mistakes

1. Ignoring Antes

Mistake: Calculating M without antes Problem: Underestimate true orbit cost Fix: Include total ante amount

2. Waiting Too Long

Mistake: Playing tight at M=6 Problem: Blinding down further Fix: Shove when M allows fold equity

3. Raising Small at Low M

Mistake: Open to 2.5bb at M=5 Problem: Committed if raised Fix: Shove or fold only

4. Ignoring Table Size

Mistake: Same M strategy 9-handed vs 5-handed Problem: Blinds hit faster short-handed Fix: Calculate effective M

Frequently Asked Questions

What's a good M-Ratio?

Green Zone (M>20) is comfortable. M<10 requires strategy changes. M<5 is push/fold territory.

How do antes affect M?

Significantly. A table with 100/200 blinds and 25×9 antes has orbit cost of 525, not 300. Always include antes.

When should I shift to push/fold?

Orange Zone (M 6-10) start incorporating more shoves. Red Zone (M 1-5) is pure push/fold.

Does position affect M strategy?

Yes. Same M but late position allows wider shoving. UTG at M=8 still needs decent hands.

How does effective M work?

Multiply M by (players/10). At 5-handed, your M=20 becomes effective M=10. Blinds hit twice as fast.

Can I rebuild from low M?

Yes, but requires luck. Double up once: M doubles. Get lucky twice from M=3: suddenly M=12.

Pro Tips

• Include antes: Orbit cost = SB + BB + all antes

• Know your zone: Strategy changes dramatically

• M 6-10 is critical: Push/fold transition

• Short-handed: Calculate effective M

• Don't wait too long: Fold equity disappears

Related Calculators

• Push/Fold Calculator - Shoving ranges
• ICM Calculator - Tournament equity
• Big Blind Calculator - Stack in BBs
• Pot Commitment Calculator - Commitment
• Tournament EV Calculator - cEV analysis

Conclusion

M-Ratio reveals your tournament stack health—how many orbits you can survive and what strategies are available. Our calculator shows your M-Zone, when to shift from normal poker to push/fold, and why Dan Harrington's concept is essential for tournament survival.

Calculate Your M-Ratio Now →

You have 15,000 chips with blinds at 400/800 plus antes. Our calculator shows you're in the Orange Zone—time to start shoving or risk blinding away with no fold equity left.