Forecast Cash Runway in Excel or Google Sheets

Use cash that’s available to fund operations. Confirm the amount against your latest bank reconciliation, and exclude restricted funds that can’t pay ordinary expenses.

The model uses these definitions:

• Starting cash: Available cash at the beginning of the first month
• Cash receipts: Cash expected to arrive during the month, regardless of when revenue was recognized
• Outflows: Recurring costs, planned hiring, and a one-time expense
• Net cash flow: Cash receipts minus total outflows
• Monthly burn: The greater of zero or negative net cash flow
• Ending cash: Starting cash plus net cash flow
• Runway: Complete forecast months before the first negative ending balance

The model reports an ending balance of exactly zero separately from a negative balance.

Start by entering this control table in Inputs!A1:B8:

Format B2 and B7 as USD, B3, B6, and B8 as dates, and B4 as an integer.

Next, enter the scenario table in Inputs!D1:G4:

Inputs!B2 is a point-in-time balance, while Inputs!B7 is a single expense. Values in Inputs!E2:G4 are nonnegative monthly cash flows.

Apply these data-validation rules:

• B2, B7, and E2:G4: number greater than or equal to zero
• B3, B6, and B8: valid first-of-month dates without time values
• B4: whole number between 1 and 60
• B5: list containing Base, Optimistic, and Conservative

For custom date validation, use this formula for B3:

=AND(ISNUMBER(B3),B3=INT(B3),DAY(B3)=1)

Change the reference to B6 or B8 for the other date cells. The cell=INT(cell) check rejects values containing a time, such as 2026-04-01 12:00.

Validation may not stop invalid pasted or imported values. For that reason, the schedule formulas return #N/A or Check inputs when required inputs are malformed.

Add these headers to Runway!A1:K1:

In A2, enter the following formula and fill it through A61:

=LET(d,Inputs!$B$3,h,Inputs!$B$4,p,ROW()-1,hOK,IFERROR(AND(ISNUMBER(h),h=INT(h),h>=1,h<=60),FALSE),dOK,IFERROR(AND(ISNUMBER(d),d=INT(d),DAY(d)=1),FALSE),IF(NOT(hOK),IF(p=1,NA(),""),IF(p>h,"",IF(dOK,EDATE(d,p-1),NA()))))

Inputs!B4 controls how many rows become active. With the sample six-month horizon, A2:A7 should contain:

2026-01-01
2026-02-01
2026-03-01
2026-04-01
2026-05-01
2026-06-01

Cells A8:A61 appear empty, but they aren’t blank. Each contains a formula returning "". This distinction matters when you build the chart in Step 8.

Now enter this formula in B2 and fill it through B61:

=IF(IFERROR(A2="",FALSE),"",IF(ROW()=2,IF(AND(ISNUMBER(Inputs!$B$2),Inputs!$B$2>=0),Inputs!$B$2,NA()),IF(ISNUMBER(I1),I1,NA())))

The first row reads starting cash from Inputs!B2. Each later active row uses the preceding month’s ending cash.

Under the Base scenario, the six active starting balances should be:

120000, 100000, 65000, 45000, 15000, -15000

Zero starting cash is valid. A blank, text, or negative opening cash value returns #N/A.

In C2, enter this cash-receipts formula and fill it through C61:

=IF(IFERROR(A2="",FALSE),"",LET(n,COUNTIF(Inputs!$D$2:$D$4,Inputs!$B$5),IF(n<>1,NA(),LET(matchRow,MATCH(Inputs!$B$5,Inputs!$D$2:$D$4,0),sourceValue,INDEX(Inputs!$E$2:$E$4,matchRow),sourceBlank,ISBLANK(INDEX(Inputs!$E$2:$E$4,matchRow)),IF(IFERROR(AND(ISNUMBER(A2),NOT(sourceBlank),ISNUMBER(sourceValue),sourceValue>=0),FALSE),sourceValue,NA())))))

The Base scenario returns 30000 in each active month.

Then enter this recurring-cost formula in D2 and fill it through D61:

=IF(IFERROR(A2="",FALSE),"",LET(n,COUNTIF(Inputs!$D$2:$D$4,Inputs!$B$5),IF(n<>1,NA(),LET(matchRow,MATCH(Inputs!$B$5,Inputs!$D$2:$D$4,0),sourceValue,INDEX(Inputs!$F$2:$F$4,matchRow),sourceBlank,ISBLANK(INDEX(Inputs!$F$2:$F$4,matchRow)),IF(IFERROR(AND(ISNUMBER(A2),NOT(sourceBlank),ISNUMBER(sourceValue),sourceValue>=0),FALSE),sourceValue,NA())))))

The Base scenario returns 50000 in each active month.

Both formulas require exactly one matching scenario. A missing or duplicated scenario, blank assumption, text amount, or negative amount returns #N/A. Numeric zero remains valid, and scenario matching is case-insensitive.

Add this formula to E2, then fill it through E61:

=IF(IFERROR(A2="",FALSE),"",LET(n,COUNTIF(Inputs!$D$2:$D$4,Inputs!$B$5),d,Inputs!$B$6,dateOK,IFERROR(AND(ISNUMBER(d),d=INT(d),DAY(d)=1),FALSE),IF(n<>1,NA(),LET(matchRow,MATCH(Inputs!$B$5,Inputs!$D$2:$D$4,0),sourceValue,INDEX(Inputs!$G$2:$G$4,matchRow),sourceBlank,ISBLANK(INDEX(Inputs!$G$2:$G$4,matchRow)),IF(IFERROR(AND(ISNUMBER(A2),dateOK,NOT(sourceBlank),ISNUMBER(sourceValue),sourceValue>=0),FALSE),IF(A2>=d,sourceValue,0),NA())))))

With a hire start of 2026-04-01, Base planned-hiring costs should be:

0, 0, 0, 10000, 10000, 10000

The cost starts in April. A blank, text, mid-month, or time-bearing hire date returns #N/A.

For the one-time expense, enter this formula in F2 and fill it through F61:

=IF(IFERROR(A2="",FALSE),"",LET(d,Inputs!$B$8,dateOK,IFERROR(AND(ISNUMBER(d),d=INT(d),DAY(d)=1),FALSE),IF(IFERROR(AND(ISNUMBER(A2),ISNUMBER(Inputs!$B$7),Inputs!$B$7>=0,dateOK),FALSE),IF(A2=d,Inputs!$B$7,0),NA())))

The six active results should be:

0, 15000, 0, 0, 0, 0

A valid first-of-month date outside the active horizon produces zeros. A blank, text, mid-month, or time-bearing date produces #N/A. A blank, text, or negative expense amount does the same.

Enter the following formulas in row 2, then fill them through row 61.

In G2, calculate total outflows:

=IF(IFERROR(A2="",FALSE),"",IF(COUNT(D2:F2)=3,SUM(D2:F2),NA()))

In H2, calculate net cash flow:

=IF(IFERROR(A2="",FALSE),"",IF(AND(ISNUMBER(C2),ISNUMBER(G2)),C2-G2,NA()))

In I2, calculate ending cash:

=IF(IFERROR(A2="",FALSE),"",IF(AND(ISNUMBER(B2),ISNUMBER(H2)),B2+H2,NA()))

In J2, classify the ending balance:

=IF(IFERROR(A2="",FALSE),"",IF(ISNUMBER(I2),IF(I2<0,"Cash negative",IF(I2=0,"Zero cash","Positive")),"Check inputs"))

In K2, calculate monthly net burn:

=IF(IFERROR(A2="",FALSE),"",IF(ISNUMBER(H2),MAX(0,-H2),NA()))

For Base January:

Ending cash = 120000 + 30000 - 50000 - 0 - 0 = 100000

Expected January results:

• Total outflows: 50000
• Net cash flow: -20000
• Ending cash: 100000
• Status: Positive
• Monthly burn: 20000

For February:

Ending cash = 100000 + 30000 - 50000 - 0 - 15000 = 65000

Together, these calculations check an ordinary month and a month containing the one-time expense.

Create this summary in Runway!M1:N3:

In N2, enter this horizon-driven formula:

=LET(h,Inputs!$B$4,hOK,IFERROR(AND(ISNUMBER(h),h=INT(h),h>=1,h<=60),FALSE),IF(NOT(hOK),"Check inputs",IFERROR(LET(cash,I2:INDEX(I:I,h+1),months,A2:INDEX(A:A,h+1),IF(COUNT(cash)<>h,"Check inputs",IF(COUNTIF(cash,"<0")=0,"Beyond forecast",MINIFS(months,cash,"<0")))),"Check inputs")))

In N3, enter:

=IFERROR(IF(N2="Beyond forecast","At least "&Inputs!$B$4,IF(AND(ISNUMBER(N2),ISNUMBER(Inputs!$B$3)),DATEDIF(Inputs!$B$3,N2,"M"),"Check inputs")),"Check inputs")

These formulas derive their ranges and wording from Inputs!B4; they don’t contain a fixed six-month count.

The Base ending-cash series should be:

100000, 65000, 45000, 15000, -15000, -45000

Expected summary:

First negative month: 2026-05-01
Full months before negative: 4

Cash remains nonnegative through April, then becomes negative during May. This result doesn’t identify the exact depletion date.

As a control, Base cash receipts total 180000, total outflows equal 345000, and June ending cash reconciles to:

120000 + 180000 - 345000 = -45000

Don’t chart A2:A61 and I2:I61 directly. Inactive cells in those ranges contain formulas returning "", which Excel can plot as trailing zeros.

Instead, create a helper range containing only active months. Add these headers:

Before entering the formulas below, leave P3:Q61 empty. Each formula spills its results down automatically.

In P2, enter:

=FILTER(A2:A61,ISNUMBER(A2:A61))

In Q2, enter:

=FILTER(I2:I61,ISNUMBER(A2:A61))

With the six-month Base forecast, P2:Q7 should contain:

Cells below the spilled results are genuinely empty, rather than formulas returning empty text.

Create a line chart from Runway!P1:Q61:

• Horizontal axis: Month
• Series: Ending Cash
• Chart title: Projected Ending Cash
• Vertical-axis label: USD

In Excel, set empty cells to display as gaps through Select Data > Hidden and Empty Cells > Gaps. Because the filtered helper leaves unused cells empty, the chart won’t add trailing zero points when the horizon is shorter than 60 months.

The line should cross below zero in May, matching Runway!N2. If the chart and summary disagree, inspect the formulas in P2:Q2, confirm that P3:Q61 doesn’t contain other values or formulas, and verify that the chart uses columns P:Q.

For an actual-versus-forecast view of burn, see the startup burn rate dashboard guide.

To compare scenarios, change only Inputs!B5. The active forecast and filtered chart range should recalculate from the corresponding scenario row.

Base

Expected ending cash:

100000, 65000, 45000, 15000, -15000, -45000

Expected summary:

First negative month: 2026-05-01
Full months before negative: 4

Optimistic

Set Inputs!B5 to Optimistic.

Expected ending cash:

108000, 81000, 69000, 49000, 29000, 9000

Expected summary:

First negative month: Beyond forecast
Full months before negative: At least 6

A positive June balance supports only “at least six months.” It doesn’t prove a longer runway unless you increase Inputs!B4 and provide assumptions for the added months.

Conservative

Set Inputs!B5 to Conservative.

Expected ending cash:

89000, 43000, 12000, -31000, -74000, -117000

Expected summary:

First negative month: 2026-04-01
Full months before negative: 3

These scenarios change cash receipts, recurring costs, and new-hire costs together. They’re planning assumptions, not probability-weighted predictions.

Run these checks in a copy of the workbook. If you use both applications, repeat them in Excel and Google Sheets. The results shown are expected from the formulas, not claims that the tests were executed.

This model has no transaction ledger, so duplicate transactions, transfers, and payment matching fall outside its scope.

Review the completed forecast for:

• Missing payroll taxes, contractors, rent, software, insurance, debt payments, and other material cash expenses
• Revenue entered when invoiced instead of cash receipts entered when collection is expected
• Text dates, mid-month dates, or hidden time values
• Formula cells overwritten with hard-coded amounts
• Scenario labels that don’t match the scenario table
• Values or formulas blocking the spilled helper ranges in P:Q
• A chart that uses A:I instead of the filtered helper range in P:Q

If you need linked income statement, balance sheet, and cash flow schedules, use a startup three-statement model instead of turning this runway schedule into a full accounting model.

ModelMonkey can use workbook context in Google Sheets and Microsoft Excel to help inspect ranges, work with formulas, analyze the forecast, and create or adjust a chart. If the workflow presents a preview, review the proposed changes before proceeding.

To check this runway model, open ModelMonkey in the workbook and submit:

Inspect Inputs!A1:G8 and Runway!A1:Q61.

The forecast horizon is controlled by Inputs!B4 and may contain 1 to 60 active monthly rows. Check active rows for formula errors, blank scenario assumptions, malformed amounts, and invalid dates, including dates with time values.

Confirm the first active month where Ending Cash in column I is below zero. Compare it with Runway!N2:N3.

Check that P2 and Q2 use FILTER formulas to return only active Month and Ending Cash values. Create or adjust a line chart from the filtered helper range in P:Q. Do not chart the fixed A2:A61 and I2:I61 ranges directly because inactive cells contain formulas returning empty text.

Do not replace missing or invalid inputs with zero. Show any proposed formulas or changes for review.

Compare its formulas, analysis, and chart with the expected Base, Optimistic, and Conservative values in this guide. ModelMonkey can assist with spreadsheet work, but it doesn’t guarantee that every formula or conclusion is correct.

Update the model on your regular planning cadence and whenever a material cash assumption changes.

For each update:

1. Replace starting cash with the reconciled opening balance for the new forecast period.
2. Update monthly cash receipts based on expected collection timing.
3. Review recurring costs for new, canceled, or repriced commitments.
4. Update the hiring date and monthly cash cost.
5. Enter the amount and month of the modeled one-time expense.
6. Increase Inputs!B4 if the result says Beyond forecast and you need a longer view.
7. Repeat the scenario and boundary checks.
8. Confirm that the chart, first-negative-month summary, and cash schedule agree.

Treat the first negative month as a planning signal. A monthly forecast shows which period needs attention, but it can’t tell you whether depletion occurs early or late within that month.