Most stores do not die because demand was weak. They die in month two because the owner ran out of cash. The cure is boring but decisive: raise enough one-time capital and a cash reserve that covers operating costs while revenue ramps. Here is the formula, with real ranges.

Why stores run out of cash in month two

A lease is signed, build-out is paid, inventory is stocked — and then sales come in slower than the model assumed. Rent, wages, and utilities keep coming whether or not customers do. Without a reserve, the first slow month is the last month. The fix is to fund the slow start before you open.

The two-part reserve formula

Your true opening capital is the sum of two pools:

PoolWhat it coversTypical range (verified 2026-08-13)
One-time costsBuild-out, first inventory, equipment, licenses, signage, contingencyBoutique/retail $30K-$150K; coffee/cafe $80K-$300K; QSR $150K-$500K; full-service restaurant $300K-$750K+
Operating reserve3-6 months of rent+NNN, wages, utilities, owner draw, other≈ 3-6 × your monthly fixed cost
Practical rule: Total opening capital = one-time costs + (monthly fixed cost × reserve months). If a lender or partner asks "how much do you need," this single number is the answer.

Monthly operating costs you must cover

LineWhat to include
Rent + NNNBase rent plus CAM, insurance, and property tax
UtilitiesPower, water, internet, phone, trash
Wages + employer taxGross wages plus FICA 7.65% + SUTA/FUTA/workers' comp (often +15-25% on payroll)
Owner drawThe wage you must pay yourself to live
OtherSoftware, marketing, supplies, maintenance, payment fees

The reserve math

Take your realistic monthly fixed cost and multiply by your reserve months. A cafe with $18,000/month fixed cost and a 4-month reserve needs $72,000 in reserve on top of its build-out and inventory. Skipping this is the single most common fatal error.

Do not skip the reserve: "I'll fund it from early sales" assumes a perfect ramp. Real ramps take 3-6 months, and card fees, employer tax, and shrinkage all land before profit does.

Put it to work

Use the free calculators below to size both pools from your own numbers, then stress-test a conservative ramp before you commit savings or a lease.