How Daily Spark calculators work

Your inputs drive the result.

Daily Spark does not silently substitute market rents, moving quotes, job prices, labor rates, income dates, or deposit-return dates. Example values are visibly labeled and appear only when you choose the example action.

Blank required fields stop the calculation. Blank optional numeric fees generally count as zero; optional comparison fields whose presence matters remain “not entered.” Impossible negative costs and zero denominators are rejected before arithmetic.

Formulas are disclosed.

Each calculator explains its main formula, included values, excluded values, and assumptions. The worked example shows how the same calculation applies to a concrete input set.

Units and money precision are explicit.

Lease calculations retain JavaScript number precision through each formula and round for display. The moving-cost tools, cash planner, and per-visit job calculations accept currency amounts to the cent and calculate monetary totals using integer cents. A fractional break-even month is displayed separately from the currency totals.

Each tool validates its accepted input ranges. Some unusual but permitted values produce a warning; values beyond a tool’s limits stop the calculation. Non-finite results are rejected rather than displayed as NaN or Infinity.

Results are estimates.

Actual costs and cash timing may vary because of taxes, billing methods, provider rules, lease language, changed dates, or omitted information.

Moving economics and upfront cash are different views.

The move or renew calculator compares the same number of months on each side. Staying cost equals renewed monthly cost times months, plus any nonrefundable renewal fee. Moving cost equals new monthly cost times months, plus nonrefundable moving expenses.

When moving costs more upfront but saves each month, break-even is the extra one-time expense divided by the monthly saving. If moving starts cheaper but costs more each month, the crossover means its early advantage ends. Equal or higher ongoing costs do not produce a fictional savings payback.

The moving budget calculator adds your itemized moving expenses and planning allowance, then separately shows refundable deposits and first-month housing cash. Deposits and prepaid first-month payments are not added again to the comparison’s economic cost. The cash total is a funding envelope, not a promise that every payment is due on the same date.

These two tools accept currency amounts to the cent and calculate totals using integer cents. Comparison months must be a whole number from 1 to 120. Blank optional expenses mean zero; missing required inputs and non-finite or negative amounts are rejected. Formula version 1.0.0, checked against the published worked examples on October 4, 2026.

Costs are held constant over your chosen period. The tools do not forecast future rent, guarantee deposit refunds, calculate taxes or legal lease-exit entitlements, or value your time and preferences.

Cash is available on a date, not just in a total.

The moving cash planner starts with the cash available on your opening date. It adds each income or refund and subtracts each payment in date order. On the same date, all payments come before incoming funds. This is a conservative modeling assumption, not a prediction of bank posting order. Dates are calendar dates, without time-of-day information.

Running balance = opening cash + incoming funds so far − payments so far. The lowest balance includes the opening cash and every event balance. Ending cash is the balance after the last included event. The first shortfall is the first event that makes the balance negative; a later positive ending balance does not erase it.

Additional starting cash to avoid a negative balance = the greater of $0 or −lowest balance. Cash needed to maintain your chosen reserve = the greater of $0 or reserve −lowest balance. The reserve is a minimum balance you choose, not a bill or a recommended amount. The reserve figure already includes the cash needed to avoid a negative balance; do not add the two figures together.

In an invented example, opening cash is $3,000 on October 10. A $2,200 payment on October 12 leaves $800; a $1,500 payment on October 14 leaves −$700; and $2,000 of income on October 16 leaves $1,300. The first gap is October 14. It takes $700 more starting cash to avoid the gap, or $1,200 more to preserve a chosen $500 reserve throughout this scenario.

Refund stress tests move entered refunds later by 7, 14, or 30 days, or exclude them, then recalculate the timeline. They do not estimate a legal deadline or likelihood of repayment. Keep earlier payments already reflected in opening cash out of the event list, and do not count transfers between accounts already included in that cash as new income. Include ordinary bills during the period; an omitted payment cannot appear in the forecast.

The planner accepts up to 50 dated events in USD, with amounts to two decimal places and labels up to 60 characters. Events cannot precede the opening date. Its calculation and restored plans use the same input validation. Formula version 1.0.0. The CFPB cash flow worksheet also explains carrying a balance forward as income and expenses occur; this planner’s event ordering and reserve rules are our own disclosed choices.

Plans remain in page memory unless you choose Save on this device. Loading and deleting a saved plan are also explicit actions; there is no automatic saving or loading. A saved plan is an editable estimate, not a bank record. See the privacy policy for device storage and local CSV exports.

Compare a job estimate with actual visits and a revised scenario.

The recurring-job profitability review subtracts the costs you include from a price per visit. Owner compensation allowance equals owner hours times the owner’s chosen hourly allowance. Employee cost equals employee person-hours times the entered employee cost per hour. Include relevant employer costs in that rate; the tool does not calculate payroll taxes or benefits.

Contribution per visit = price − owner allowance − employee cost − supplies − other costs − allocated overhead − fixed fee − percentage fee. Owner allowance, employee cost, and percentage fees are each rounded to the nearest cent before subtraction. A positive contribution means money remains after those included amounts; it is not a complete accounting profit or a tax calculation.

In an invented example, a $160 visit with a $90 owner allowance, $30 in supplies and travel expenses, and $15 allocated overhead leaves $25. Another owner hour valued at $30 makes that −$5. These are illustrative inputs, not recommended prices or pay rates.

In the estimate, employee count excludes the owner. Employee person-hours equal employee count times each employee’s on-site and travel hours. Actual visits use the total owner hours and total employee person-hours you enter for each visit. Actual-visit comparisons use the current entered price, rates, overhead, and fees; they are not an immutable record of historical pay or prices. Entering two employees for two hours means four employee person-hours, not four elapsed hours.

The review sums rounded per-visit amounts before calculating the arithmetic average of up to 12 actual visits. An average can contain a fraction of a cent and is rounded for display. A revised scenario replaces the chosen price, hours, supplies, and other costs. Weekly contribution equals its per-visit contribution times visits per week, rounded once to the nearest cent with exact half cents rounded away from zero. Changing frequency scales both revenue and included per-visit costs; it does not remove the underlying work.

Price targets search for the lowest cent price that meets the selected contribution after the rounded percentage fee. A target beyond the supported price range is reported as unavailable. Owner capacity uses owner time only; it is not a team rota, route plan, or guarantee that visits fit the calendar. Zero owner hours cannot establish a meaningful maximum number of visits.

Omitted costs, unpaid work, cancellations, demand, collection delays, tax obligations, and changes to the customer agreement remain outside the calculation. Allocated overhead is your chosen per-visit assumption; it is not automatically reallocated across the business when visit frequency changes. Formula version 1.0.0.

Inputs stay in page memory unless you choose the device-save action. Loading, deleting, and CSV export are also deliberate actions. No customer account, remote job database, or AI result generation is involved. See the privacy policy for local storage and exported-file limits.

Effective rent calculator

1. Weekly rent equivalent = base monthly rent × 12 ÷ 52.
2. Total concession = free months × base rent + free weeks × weekly equivalent + rent credit.
3. Net base rent = the greater of zero or gross base rent minus total concession.
4. Effective all-in monthly cost = net rent ÷ lease months + recurring monthly fees + one-time fees ÷ lease months.

Version 1.0.0 · reviewed 2026-08-28. See the calculator page for the worked example, inclusions, exclusions, and practical interpretation.

True apartment cost calculator

1. Total nonrefundable cost = concession-adjusted net rent + recurring fees over the lease + nonrefundable upfront charges.
2. Effective monthly total = total nonrefundable cost ÷ lease months.
3. Cash before credit = rent due now + recurring charges due now + nonrefundable upfront charges + deposit.
4. Estimated move-in cash = the greater of zero or cash before credit minus the entered upfront credit.

Version 1.0.0 · reviewed 2026-08-28. See the calculator page for the worked example, inclusions, exclusions, and practical interpretation.

Apartment comparison calculator

1. Each apartment’s effective all-in monthly cost uses the shared lease formula.
2. Monthly cost including commute = effective all-in housing cost + entered monthly commute expense.
3. Full commitment including commute = nonrefundable lease cost + monthly commute expense × lease months.
4. Common-period cost = full-lease average monthly cost including commute × common comparison months. Compare these amounts, not unequal lease totals.
5. Monthly cost per square foot = effective all-in housing cost ÷ entered square footage.

Version 1.1.0 · reviewed 2026-09-06. See the calculator page for the worked example, inclusions, exclusions, and practical interpretation.

Known examples anchor every formula.

Unit tests cover the published examples, decimal inputs, blank optional fields, negative-value rejection, zero denominators, concession caps, formatting boundaries, and output finiteness. Route checks verify headings, metadata, canonical structure, internal links, and server-rendered content.

The tests establish that the disclosed formulas are implemented as written; they do not turn user assumptions into official quotes.

Formula changes receive a version change.

A material arithmetic correction updates the affected tests, methodology, formula version, and review date. Wording-only changes do not pretend that every formula was re-reviewed.

Report a reproducible issue to puzzledrizzlemaster@gmail.com.