Co-Founder Equity Split Tracker: Google Sheets Calculator
Split equity wrong on day one, and you're paying for it for 10 years. This tool lets you model co-founder equity scenarios, understand vesting mechanics, and benchmark against what actually works.
Tool #10 in the Fundraising Hub
Split equity wrong on day one, and you’re paying for it for 10 years. This tool lets you model co-founder equity scenarios, understand vesting mechanics, and benchmark against what actually works.
The Problem Co-Founders Get Wrong
Most founding teams make equity decisions in 30 minutes over coffee, then wonder why tension erupts at month 18 when vesting accelerates or someone wants to leave.
What happens without this tool:
- You split 50/50 because “it’s fair,” then one co-founder works 60 hours/week and the other works 20
- You don’t agree on a vesting schedule, and suddenly Person A wants to take equity off the table at month 14
- Someone leaves at year 2, and you don’t know if they take vested equity, partially vested equity, or nothing
- You’re raising Series A and your cap table looks like a startup graveyard (15 different equity events, no consistency)
What this tool prevents:
- You model equity allocation based on contribution factors, not ego
- You visualize what happens if someone leaves at 6 months, 12 months, 24 months, etc.
- You understand vesting impact month-by-month
- You have a cap table that investors don’t laugh at
How to Set Up This Google Sheet
Create a Google Sheet with these tabs (instructions for formulas below):
- Inputs — Where you enter assumptions
- Vesting Schedule — Month-by-month equity visualization
- Departure Scenarios — What happens if someone leaves
- Fair-Split Calculator — Allocation based on contribution
- Benchmarks — How your split compares to market
- Negotiation Tracker — Document agreements and changes
Tab 1: Inputs (Setup Page)
This is where you plug in your assumptions. Everything else on the sheet will calculate automatically.
Input Section: Co-Founder Information
Create a table like this:
| Field | Co-Founder A | Co-Founder B | Co-Founder C |
|---|---|---|---|
| Name | [Name] | [Name] | [Name] |
| [Email] | [Email] | [Email] | |
| Role | CEO | CTO | CPO |
| Start Date | 2024-01-15 | 2024-01-15 | 2024-02-01 |
| Vesting Grant (%) | 10% | 10% | 5% |
| Cliff Period (months) | 12 | 12 | 12 |
| Vesting Period (months) | 48 | 48 | 48 |
| Vesting Schedule | Monthly | Monthly | Monthly |
Input Section: Vesting Assumptions
| Assumption | Value | Notes |
|---|---|---|
| Total Equity Pool | 100% | All percentages = 100% |
| Company Founding Date | 2024-01-15 | Used to calculate vesting start |
| Today’s Date | 2024-04-11 | Auto-update this; use =TODAY() formula |
| Acceleration on Exit | 50% | How much equity accelerates if sold (0-100%) |
Input Section: Scenario Planning
| Scenario | Co-Founder | Departure Date | Acceleration (Yes/No) |
|---|---|---|---|
| Scenario 1 | Co-Founder A | 2024-07-15 (6 months) | No |
| Scenario 2 | Co-Founder B | 2025-01-15 (12 months) | No |
| Scenario 3 | Co-Founder A | 2025-07-15 (18 months) | Yes |
| Scenario 4 | Co-Founder C | 2026-01-15 (24 months) | No |
Formulas for Inputs Tab:
Today’s Date: =TODAY() Months Since Founding: =DATEDIF(B3, B4, “M”)
Tab 2: Vesting Schedule (The Core Calculator)
This tab shows month-by-month how much equity each co-founder has vested.
Vesting Schedule Table
Create columns for each month, starting from the founding date:
| Month | Date | Months Since Start | Co-Founder A (Vested %) | Co-Founder B (Vested %) | Co-Founder C (Vested %) | Co-Founder A (Raw %) | Co-Founder B (Raw %) | Co-Founder C (Raw %) |
|---|---|---|---|---|---|---|---|---|
| 0 | 2024-01-15 | 0 | 0% | 0% | 0% | 10% | 10% | 5% |
| 1 | 2024-02-15 | 1 | 0% | 0% | 0% | 10% | 10% | 5% |
| … | … | … | … | … | … | … | … | … |
| 12 | 2025-01-15 | 12 | 2.5% | 2.5% | 0% | 10% | 10% | 5% |
| … | … | … | … | … | … | … | … | … |
| 24 | 2026-01-15 | 24 | 5% | 5% | 0% | 10% | 10% | 5% |
| … | … | … | … | … | … | … | … | … |
| 48 | 2028-01-15 | 48 | 10% | 10% | 5% | 10% | 10% | 5% |
Vesting Formula (Core Logic)
For each co-founder in month N, use this formula:
=IF(
MONTHS_SINCE_START < CLIFF_PERIOD,
0,
MIN(
(MONTHS_SINCE_START - CLIFF_PERIOD) / (VESTING_PERIOD - CLIFF_PERIOD) * TOTAL_GRANT,
TOTAL_GRANT
)
)
In Google Sheets format (for Co-Founder A, Month 13):
=IF(
C13 < $B$8,
0,
MIN(
(C13 - $B$8) / ($B$9 - $B$8) * $B$7,
$B$7
)
)
Where:
- C13 = Months since start (in that row)
- $B$8 = Cliff period (locked reference to Inputs tab)
- $B$9 = Vesting period (locked reference)
- $B$7 = Vesting grant % (locked reference)
Key vesting mechanics:
- Cliff period (12 months): No equity vests until month 12. Then you get 1/4 of your grant.
- Monthly vesting (months 13-48): You vest 1/48th of your grant each month.
- Year 1 vest: After 12 months, you have 2.5% (1/4 of 10%)
- Year 4 vest: After 48 months, you have 100% of your grant
Example: Co-Founder A Vesting Schedule
| Month | Months Since Start | Status | Vested % | Notes |
|---|---|---|---|---|
| 0-11 | 0-11 | Before Cliff | 0% | Nothing vests |
| 12 | 12 | At Cliff | 2.5% | 1/4 of 10% grant cliff |
| 13 | 13 | Post-Cliff | 2.604% | 2.5% + (1/48 × 10%) |
| 24 | 24 | Year 2 | 5% | 1/2 of grant vested |
| 36 | 36 | Year 3 | 7.5% | 3/4 of grant vested |
| 48 | 48 | Year 4 | 10% | 100% of grant vested |
Tab 3: Departure Scenarios (The “What If” Tab)
This tab answers: “What happens if Co-Founder A leaves at month 18?”
Departure Scenarios Table
Create one section per scenario:
SCENARIO 1: Co-Founder A Leaves at Month 6 (No Acceleration)
Departure Date: 2024-07-15 Months at Company: 6 Vesting Status at Departure:
- Cliff: 12 months (NOT REACHED)
- Vested Equity: 0%
- Unvested Equity: 10%
Outcome:
- Equity Kept: 0%
- Equity Forfeited: 10%
- Remaining Cap Table:
- Co-Founder A: 0%
- Co-Founder B: 10%
- Co-Founder C: 5%
- Available for future hiring: 85%
SCENARIO 2: Co-Founder B Leaves at Month 12 (No Acceleration)
Departure Date: 2025-01-15 Months at Company: 12 Vesting Status at Departure:
- Cliff: 12 months (REACHED)
- Vested Equity: 2.5%
- Unvested Equity: 7.5%
Outcome:
- Equity Kept: 2.5%
- Equity Forfeited: 7.5%
- Remaining Cap Table:
- Co-Founder A: 10%
- Co-Founder B: 2.5% (if they don’t want it back, available for pool)
- Co-Founder C: 5%
- Available for future hiring: 82.5%
SCENARIO 3: Co-Founder C Leaves at Month 24 (With 50% Acceleration)
Departure Date: 2026-01-15 Months at Company: 24 Vesting Status at Departure:
- Cliff: 12 months (REACHED)
- Vested Equity: 2.5%
- Unvested Equity: 2.5%
- Accelerated Equity (50% of unvested): 1.25%
Outcome:
- Equity Kept (without acceleration): 2.5%
- Accelerated Equity: 1.25% (additional)
- Total Equity Kept: 3.75%
- Equity Forfeited: 1.25%
- Remaining Cap Table:
- Co-Founder A: 10%
- Co-Founder B: 10%
- Co-Founder C: 3.75%
- Available for future hiring: 76.25%
Formulas for Departure Scenarios
Vested at Departure:
=IF(
MONTHS_AT_DEPARTURE < CLIFF,
0,
MIN(
(MONTHS_AT_DEPARTURE - CLIFF) / (VESTING_PERIOD - CLIFF) * TOTAL_GRANT,
TOTAL_GRANT
)
)
Accelerated Equity (if applicable):
=Vested_at_Departure + (Unvested_at_Departure × Acceleration_Rate)
Tab 4: Fair-Split Calculator
This is where you use contribution factors to decide allocation, rather than just gut feel.
Contribution Factors
Rate each co-founder on these dimensions (scale 1-5, where 5 is maximum):
| Factor | Definition | Co-Founder A | Co-Founder B | Co-Founder C | Notes |
|---|---|---|---|---|---|
| Idea | Did you conceive the original idea? | 5 | 4 | 2 | A had the insight; B shaped it; C came later |
| Capital | Did you fund the company (pre-raise)? | 3 | 1 | 0 | A put in $25K; B contributed sweat; C had no capital |
| Execution | Who does the work day-to-day? | 4 | 5 | 3 | B ships code; A handles strategy; C part-time |
| Network | Who brings customer/investor connections? | 4 | 2 | 5 | A has deep startup network; C has enterprise customers |
| Domain Expertise | Who understands the market deeply? | 3 | 4 | 5 | C is former VP of this industry |
| TOTAL POINTS | (Sum of all factors) | 19 | 16 | 15 | |
| Allocation % | (Points / Total × 100%) | 42% | 35% | 23% |
How to Use This
- Rate each co-founder on each factor (1-5 scale)
- Sum the points for each person
- Calculate allocation %: (Person’s Points / Total Points) × 100%
- Apply additional adjustment if needed (e.g., “B is joining later, so we’ll discount by 10%“)
Example Output
Fair allocation (before later adjustments):
- Co-Founder A: 42% (Idea + Capital + Execution)
- Co-Founder B: 35% (Strong Execution + Domain Knowledge)
- Co-Founder C: 23% (Joining later, but strong Network)
Adjusted allocation (accounting for timing):
- Co-Founder A: 10% (but came at founding)
- Co-Founder B: 8.75% (joined 2 weeks later, pro-rated)
- Co-Founder C: 5% (joined 2 weeks later, pro-rated)
- Option pool: 76.25% (for future hires)
Tab 5: Benchmarks (How You Compare to Market)
Typical Equity Splits by Team Size
| Team Composition | Typical Splits | Context |
|---|---|---|
| 2 Co-Founders (Equal Contribution) | 50% / 50% | Each person important, equal investment |
| 2 Co-Founders (Unequal) | 60% / 40% | One person has more idea/capital/network |
| 3 Co-Founders (Equal) | 33% / 33% / 33% | All equal, all important |
| 3 Co-Founders (Unequal) | 40% / 35% / 25% | Idea person + strong executor + support |
| 3 Co-Founders (Late Joiner) | 40% / 40% / 20% | One person joins at month 2-3 |
| 4+ Co-Founders | 25% / 25% / 25% / 25% (rare) | Usually splits are 30/30/25/15 or similar |
Option Pool Benchmarks
| Stage | Typical Option Pool | Notes |
|---|---|---|
| Pre-Seed | 15-20% | Often held by founders or advisors |
| Seed | 20-30% | Reserve for key hires before Series A |
| Series A | 15-20% | Fresh pool created in fundraise |
| Series B+ | 10-15% | Pool diluted but mostly allocated |
Rule of thumb: At seed stage, reserve 20% for option pool before splitting the remaining 80% between co-founders.
Vesting Schedule Benchmarks
| Element | Market Standard | Range |
|---|---|---|
| Cliff Period | 12 months | 6-12 months (usually 1 year) |
| Vesting Period | 48 months (4 years) | 36-60 months |
| Monthly Vesting | 1/48th of grant per month | 1/36th to 1/60th depending on period |
| Year 1 Vest | 25% (1/4 of grant) | 20-25% typical |
| Acceleration on Exit | 0-100% | Usually 0% (double trigger) or 50% (single trigger) |
| Acceleration Trigger | ”Double trigger” (change of control + termination) | Single trigger = automatic acceleration |
Double trigger explanation: You only accelerate if (1) there’s an exit/acquisition AND (2) you’re terminated or asked to resign. This protects investors.
Tab 6: Negotiation Tracker
Document what you’ve actually agreed to, so there’s no confusion later.
Co-Founder Agreement Record
| Item | Agreed Value | Notes | Date Agreed | Confirmed By |
|---|---|---|---|---|
| Co-Founder A Equity | 10% | CEO, full-time from Day 1 | 2024-01-10 | |
| Co-Founder B Equity | 10% | CTO, full-time from Day 1 | 2024-01-10 | |
| Co-Founder C Equity | 5% | CPO, joining Week 3 | 2024-01-25 | Signed Doc |
| Vesting Cliff | 12 months | Standard 1-year cliff | 2024-01-10 | |
| Vesting Period | 48 months | 4-year total vesting | 2024-01-10 | |
| Acceleration | 50% on exit | Single-trigger acceleration | 2024-01-10 | |
| Departure at 6mo | Forfeit all equity | If they leave before cliff | 2024-01-10 | |
| Departure at 12mo | Keep 2.5%, lose 7.5% | If they leave at cliff | 2024-01-10 | |
| Option Pool | 15% | Reserved for future hires | 2024-02-01 | Board Approval |
What to Include
- Equity amounts (as % of total company)
- Vesting schedule details (cliff + period)
- Acceleration terms (conditions under which vesting accelerates)
- Departure clauses (what happens if someone leaves at 6mo, 12mo, 24mo, etc.)
- Bring-along rights (if you sell the company, they must sell too)
- Tag-along rights (if someone else sells, they can too at same price)
- IP assignment (all company IP belongs to company, not individuals)
- Non-compete / non-solicitation (usually 1-2 years)
Real-World Examples
Example 1: Two Equal Co-Founders
Scenario: You and your best friend start a company on January 1. You contribute the idea and your network. They contribute domain expertise and willingness to do the grunt work.
Fair Split Calculation:
- You: Idea (5) + Network (4) + Capital (2) = 11 points
- Them: Domain (5) + Execution (5) + Capital (0) = 10 points
- Total: 21 points
- Your allocation: 11/21 = 52.3% → Round to 50%
- Their allocation: 10/21 = 47.6% → Round to 50%
Decision: Start with 50/50 equity (including vesting).
- You: 50% vesting over 4 years with 1-year cliff
- Them: 50% vesting over 4 years with 1-year cliff
- Option pool: 0% (you’ll adjust this when raising)
Vesting schedule:
- Month 0-11: Both have 0 equity
- Month 12: Both have 12.5% (1/4 vested)
- Month 24: Both have 25% (1/2 vested)
- Month 48: Both have 50% (fully vested)
If you leave at month 14: You have 12.5% + (1/48 × 50%) = 13.04% vested. You keep 13%, they can repurchase the other 36.96% at cost, or it goes back to the pool.
Example 2: Three Co-Founders, Different Contribution Times
Scenario: You start January 1. Co-Founder B joins February 1 (1 month later, full-time). Co-Founder C joins March 1 (2 months later, part-time).
Fair Split Calculation:
- You (CEO, founder): Idea (5) + Execution (4) + Capital (3) = 12 points
- B (CTO, full-time from month 2): Execution (5) + Domain (4) = 9 points
- C (Advisor/CPO, part-time from month 3): Network (5) + Domain (3) = 8 points
- Total: 29 points
Allocation (before timing adjustment):
- You: 12/29 = 41.4% → 10% grant
- B: 9/29 = 31% → 8% grant
- C: 8/29 = 27.6% → 7% grant
- Option pool: 75%
Then apply timing adjustment (joining later = slightly lower):
- You: 10% (from day 1)
- B: 8% (joined month 2, pro-rated at 97% = 7.76% → 8%)
- C: 5% (joined month 3, part-time, pro-rated at 87% = 6% → 5%)
- Option pool: 77%
Vesting: All use 4-year vesting with 1-year cliff, monthly vesting.
Example 3: What Happens If Someone Leaves (Scenario Analysis)
Initial allocation:
- Co-Founder A: 10%
- Co-Founder B: 10%
- Co-Founder C: 5%
- Option pool: 75%
Scenario 1: Co-Founder A leaves after 8 months
- Vested: 0% (before cliff)
- They forfeit 10%, it goes back to pool
- New pool: 75% + 10% = 85%
- Cap table: B (10%), C (5%), Pool (85%)
Scenario 2: Co-Founder B leaves after 16 months
- Vested: 2.5% + (1/48 × 10%) = 2.604%
- They keep 2.604%, forfeit 7.396%
- New pool: 75% + 7.396% = 82.396%
- Cap table: A (10%), C (5%), B (2.604%), Pool (82.396%)
Scenario 3: Co-Founder C leaves after 36 months with 50% acceleration
- Vested without acceleration: 5% × (24/48) = 2.5%
- Unvested: 2.5%
- Accelerated (50% of unvested): 1.25%
- Total vested: 3.75%
- Forfeited: 1.25%
- New pool: 75% + 1.25% = 76.25%
- Cap table: A (10%), B (10%), C (3.75%), Pool (76.25%)
How Investors React to Your Equity Structure
Red Flags Investors See
Four co-founders with 25% each, 0% option pool → “How will you hire anyone?”
Vesting cliff of 6 months → “That’s too short; you’re not committed.”
No acceleration clause, even on exit → “You’re not aligned with founders after exit.”
Co-founder joined in month 6 with same equity as founder → “You don’t understand contribution-based allocation.”
10 separate equity events with different vesting schedules → “You don’t have a coherent cap table strategy.”
Green Flags Investors See
2-3 co-founders, well-defined equity split (50/50 or 40/30/30) → “The founding team is balanced and thoughtful.”
4-year vesting with 1-year cliff → “Standard, committed structure.”
15-20% option pool reserved → “They’ve thought about hiring strategy.”
Different vesting start dates if co-founders joined at different times → “They understand fairness and timing.”
Clear cap table with no surprises → “This founder is organized.”
When to Update Your Equity Structure
Trigger 1: New Co-Founder Joins
- Add them to the vesting schedule
- Adjust option pool (typically reduces it)
- Update “Negotiation Tracker” with new agreement
Trigger 2: Someone Leaves
- Update vesting status (vested vs. forfeited)
- Update cap table with new pool size
- Document departure terms in “Negotiation Tracker”
Trigger 3: You’re Raising (Pre-Seed, Seed, Series A)
- Investors will ask for cap table
- This sheet IS your cap table defense
- You can show how you allocated equity fairly
- You can show how your founding team is committed (vesting schedules)
Trigger 4: You Want to Adjust or Give Options
- Use “Fair-Split Calculator” to model new hires
- Show co-founders the data behind the decision
- Update “Vesting Schedule” to include new hire
- Update “Negotiation Tracker”
Key Formulas You Need (Copy/Paste Ready)
Formula 1: Calculate Vested Equity (Monthly)
=IF(
MONTHS_SINCE_START < CLIFF_MONTHS,
0,
MIN(
(MONTHS_SINCE_START - CLIFF_MONTHS) / (VESTING_MONTHS - CLIFF_MONTHS) * GRANT_PERCENT,
GRANT_PERCENT
)
)
Formula 2: Calculate Points for Fair Split
=SUM(Idea_Score, Capital_Score, Execution_Score, Network_Score, Domain_Score)
Formula 3: Calculate Allocation Percentage
=PERSON_POINTS / SUM(ALL_PERSON_POINTS)
Formula 4: Calculate Months Since Start
=DATEDIF(START_DATE, TODAY(), "M")
Formula 5: Calculate Accelerated Equity (Single-Trigger)
=Vested_Equity + (Unvested_Equity * Acceleration_Rate)
The One Sheet That Prevents Co-Founder Conflict
Build this sheet on day 1, share it with your co-founders, and revisit it quarterly. It’s the difference between “We shook hands and said 50/50” and “We have a documented, fair, transparent equity structure.”
Pro tip: Print this sheet and sign it. Have each co-founder sign the “Negotiation Tracker” section. You don’t need a lawyer for basic equity alignment; you just need transparency.
By the time you’re raising Series A, your cap table will look professional, organized, and intentional. That’s when investors know you’ve thought about the details.
Next Steps
- Copy the Google Sheet template (linked in the fundraising hub)
- Fill in your co-founder details on the Inputs tab
- Watch the Vesting Schedule tab populate automatically
- Run the Departure Scenarios to understand “what if”
- Use the Fair-Split Calculator to justify your allocation
- Sign the Negotiation Tracker with your co-founders
- Share this with investors (they will be impressed by your thoughtfulness)
Your equity structure is the foundation of your cap table. Build it right from day one.