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CRE Debt Yield, Loan Constant & Leverage Spread Formula
Underwrite commercial real estate via Debt Yield = NOI / Loan, Monthly-Pay Annual Loan Constant k_debt, DSCR = Debt_Yield / k_debt, and Positive vs Negative Cash-on-Cash Leverage.
Read the guide →Dynamic ArraysCreate a date sequence between two dates with SEQUENCE
Generate an inclusive daily or weekly calendar column dynamically from StartDate and EndDate using SEQUENCE(End - Start + 1, 1, Start, 1).
Read the guide →TextCreate a project-specific URL matching key
Build a simplified host/path comparison key only where your project explicitly treats these URL variants as equivalent.
Read the guide →TextCreate display masks for synthetic identifiers and email addresses
Practice last-four display masking with synthetic text values. A masked output does not remove or secure the original data.
Read the guide →TextCreate standardized email addresses from first and last name columns
Build lowercase first.last@domain email addresses while stripping stray spaces and apostrophes from multi-part surnames.
Read the guide →Healthcare & ClinicalCRIB II (Clinical Risk Index for Babies II) Preterm NICU Score (0–27)
Calculate Gareth Parry’s treatment-independent CRIB II neonatal mortality score (0–27 points) for preterm infants <= 32 weeks gestation from sex-specific birthweight/GA points, admission temperature, and base excess.
Read the guide →Project Management & Operations ResearchCritical Chain Root-Sum-of-Squares Buffer Formula
Pool task contingencies into Eliyahu Goldratt’s (1997) Critical Chain Project Buffer PB_SSQ = SQRT(SUM((P90_i - P50_i)^2)) and monitor execution with the Fever-Chart Buffer Burn Index.
Read the guide →Statistical & MathCronbach’s Alpha (alpha) Internal Consistency & Spearman-Brown Prophecy
Calculate psychometric test reliability Cronbach’s alpha = (K / (K - 1)) * (1 - Sum_Item_Var / Total_Score_Var) and Spearman-Brown predicted reliability for scaled test length.
Read the guide →FX Derivatives & International Money MarketsCross-Currency Basis & CIP Deviation Formula
Calculate 1-Year FX Forward Premium, FX-Swapped Synthetic USD Rate, Du-Tepper-Verdelhan Cross-Currency Basis Spread (bps), and Hedged USD Cash-Lender Arbitrage Pickup.
Read the guide →Petroleum Refining & Midstream BlendingCrude Oil API Gravity & Pipeline Blend Formula
Convert API Gravity to 60°F Specific Gravity SG = 141.5 / (API + 131.5), compute Exact Volumetric Blended Specific Gravity, and recover True Blended API Gravity without linear-API averaging error.
Read the guide →Healthcare & Clinical CalculationsCRUSADE In-Hospital Major Bleeding Score for NSTEMI (1–96)
Calculate Sumeet Subherwal’s 8-domain CRUSADE Bleeding Risk Score (1–96 points across Hematocrit, CrCl, Heart Rate, Sex, CHF Signs, Prior Vascular Disease, Diabetes, and Systolic BP) to tailor radial access and antithrombotic dosing in NSTEMI.
Read the guide →Industrial Gases, Cryogenic Distillation & Steel/Gasification UtilitiesCryogenic Air Separation Unit (ASU) Oxygen & Power Formula
Calculate Cryogenic ASU Dry-Air Intake Flow (Nm³/hr), Daily Pure Oxygen Tonnage (t/day), Main Air Compressor Power (MW), and Total Pipeline GOX Electrical Load (MW).
Read the guide →Medical Imaging Physics, Computed Tomography (CT) QA & Radiodensity WindowingCT Hounsfield Unit (HU) & Display Window Grayscale Formula
Calculate Calibrated Hounsfield Unit HU = 1000*(mu_x - mu_water)/(mu_water - mu_air), Lower/Upper Display Window Bounds, and 8-Bit Monitor Grayscale Intensity (0–255).
Read the guide →Math & TrigCube root and nth root formula: positive and negative numbers
Raise numbers to fractional exponent ^(1/n) for any root degree, and pair SIGN with ABS for negative odd roots.
Read the guide →StatisticalCumulative (expanding) average formula: AVERAGE($B$2:B5)
Track season-to-date or year-to-date running averages with an expanding range $B$2:B2 that locks row 2 and grows automatically as you copy down.
Read the guide →Finance & AccountingCumulative Loan Principal & Interest Paid Between Two Periods (FV & PMT)
Calculate exact cumulative principal and cumulative interest paid between any start period s and end period e without building a 360-row amortization schedule using FV balance differences.
Read the guide →Clinical Medicine & PhysiologyCunningham RMR Formula (1980 & 1991): Fat-Free Mass Athlete Metabolic Rate Calculator
Calculate athletic Resting Metabolic Rate from body-composition Fat-Free Mass FFM = Weight * (1 - BodyFat% / 100) using John J. Cunningham’s classic 1980 athlete equation (500 + 22 * FFM_kg) and 1991 general LBM equation (370 + 21.6 * FFM_kg).
Read the guide →StatisticalCURB-65 and qSOFA: separate score formulas with boundary tests
Practice IF and OR using fictional CURB-65 and qSOFA inputs, explicit units and separate mental-status criteria.
Read the guide →Engineering & ScienceCurie-Weiss Paramagnetic Susceptibility & Effective Bohr Magneton (mu_eff)
Calculate molar magnetic susceptibility chi_m = C / (T - theta_CW) above magnetic ordering temperatures and extract unpaired d/f-electron effective moment mu_eff = SQRT(8 * C_cgs) in Bohr magnetons (mu_B).
Read the guide →FinancialCurrency conversion formula: cross-currency FX table with XLOOKUP
Convert between any pair of currencies (EUR to USD, EUR to GBP, JPY to EUR) from a single USD-anchored FX table—no N-by-N matrix needed.
Read the guide →EngineeringCurrent Divider Rule & Thevenin Maximum Power Transfer Theorem formulas
Split parallel branch currents using opposite resistance I_1 = I_total * (R_2 / (R_1 + R_2)) and verify Thevenin load power P_L = V_th^2 * R_L / (R_th + R_L)^2 peaking at R_L = R_th.
Read the guide →FinancialCurrent Ratio, Quick Ratio (Acid-Test), and Net Working Capital (NWC)
Calculate current and quick ratios and compare total working capital with one explicitly defined operating-working-capital measure.
Read the guide →Date & TimeCustom 1-letter ("MTWRFSU") & 2-letter weekday abbreviations (WEEKDAY, MID & CHOOSE)
Map numeric dates to explicitly chosen one- or two-letter weekday labels, independently of localized weekday names.
Read the guide →Data Validation & AuditingCustom Data Validation: Numbers Only, Text Only, Whole %, & Weekdays Only
Enforce strict type, whole-percentage integer step, and Monday–Friday business-day rules on intake rows using ISNUMBER, ISTEXT, MOD, and WEEKDAY(date, 2) <= 5.
Read the guide →Dynamic arraysCustom sort order with formula: rank Critical, High, Medium, Low using SORTBY
Map non-alphabetical status labels to a custom priority table with XMATCH and sort rows automatically via SORTBY.
Read the guide →FinancialCustomer Lifetime Value (LTV), LTV:CAC ratio, and CAC Payback formula
Calculate gross-margin-adjusted Customer Lifetime Value (ARPU * GrossMargin / Churn), LTV:CAC ratio, and months to recover Customer Acquisition Cost.
Read the guide →ScienceCyclotron Frequency, Larmor Gyroradius & MRI Proton Larmor Frequency
Calculate charged-particle Cyclotron Frequency f_c = |q| * B / (2 * PI() * m) (MHz), magnetic Larmor Gyroradius r_L = (m * v_perp) / (|q| * B) (mm), and 1H MRI nuclear Larmor resonance (42.577 MHz/T).
Read the guide →Crystal Growth, Silicon Wafer Boules & Dopant SegregationCzochralski Silicon Ingot Dopant Segregation Profile Formula
Calculate Seed-End Crystal Dopant Concentration C_s(0), Solidified-Fraction Ingot Concentration C_s(g), Enriched Crucible Melt Concentration C_L(g), and Tail-to-Seed Resistivity Drift Ratio.
Read the guide →Political Economy, Governance & Resource Allocationd’Hondt vs Sainte-Laguë Seat Apportionment Formula
Compare Victor d’Hondt (divisors 1, 2, 3) against André Sainte-Laguë (odd divisors 1, 3, 5) highest-averages apportionment using LARGE and COUNTIF across multi-party seat allocations.
Read the guide →Transportation Logistics & Last-Mile OperationsDaganzo Milk-Run Vehicle Routing Length Formula
Estimate multi-stop fleet tour mileage using Carlos Daganzo’s (1984) continuous approximation L_fleet = 2 * r_stem * m_tours + k_tsp * SQRT(N_stops * Area) and quantify consolidation savings.
Read the guide →EngineeringDalton partial pressure and Henry equilibrium concentration formulas
Calculate ideal-mixture partial pressure and dilute-solution equilibrium concentration with an explicitly defined Henry solubility coefficient.
Read the guide →Engineering & ScienceDamköhler Number (Da): Isothermal First-Order CSTR vs. PFR Conversion
Calculate the first-order reactor Damköhler number Da = k * tau and compare continuous stirred-tank conversion X_CSTR = Da / (1 + Da) against plug-flow conversion X_PFR = 1 - EXP(-Da).
Read the guide →Healthcare & ClinicalDAPT Score (Yeh 2016) Prolonged Dual Antiplatelet Therapy Formula (-2 to +10)
Calculate Robert Yeh’s ACC/AHA-endorsed DAPT Study Score (-2 to +10 points) after 12 event-free months post-coronary stenting—balancing older-age bleeding penalty (-2 or -1) against 8 ischemic stent-thrombosis predictors (+1 or +2) around the >= 2 continuation cutoff.
Read the guide →EngineeringDarcy-Weisbach pipe friction head loss (hf) and pressure drop (kPa) formula
Calculate major pipe friction head loss in meters (hf = f*(L/D)*(v^2/2g)) and pressure drop in kilopascals (kPa) across water, HVAC, and process piping.
Read the guide →EngineeringDarcy's Law Groundwater Flow, Hydraulic Gradient & Pore Seepage Velocity
Compute signed Darcy discharge, hydraulic gradient, specific discharge and average pore-water velocity under a one-dimensional saturated-flow model.
Read the guide →Engineering & ScienceDarken's Equations: Alloy Interdiffusion Coefficient & Kirkendall Marker Velocity
Calculate the chemical interdiffusion coefficient D_tilde = (1 - X_A) * D_A + X_A * D_B and Kirkendall inert-marker velocity v_K = (D_A - D_B) * (dX_A / dx) in solid-state diffusion couples and solder joints.
Read the guide →Renewable Wind Energy & Distributed Aerodynamics, Darrieus Lift vs Savonius Drag VAWTDarrieus & Savonius VAWT Solidity, TSR & Torque Formula
Calculate Vertical-Axis Wind Turbine Blade Chord Solidity (N*c/R), Tip-Speed Ratio lambda, Rectangular Swept-Area Shaft Power (kW), and Aerodynamic Rotor Torque (N·m).
Read the guide →Healthcare & Clinical CalculationsDAS28-ESR & DAS28-CRP Rheumatoid Arthritis Activity Calculator
Calculate EULAR 28-joint Disease Activity Scores DAS28-ESR and DAS28-CRP from Tender Joint Count (0–28), Swollen Joint Count (0–28), ESR (mm/h) or CRP (mg/L), and Patient Global VAS (0–100 mm).
Read the guide →Math & TrigDashboard SUMIFS with an "All" dropdown option
Switch cleanly between total revenue when a filter cell equals "All" and filtered SUMIFS when a specific category is chosen.
Read the guide →Cloud Infrastructure & Sustainability AnalyticsData Center PUE, DCiE, CUE & WUE Efficiency Formula
Audit ISO/IEC 30134-2 Power Usage Effectiveness PUE = Total_Facility_Energy / IT_Energy, DCiE = 1 / PUE, Carbon Usage Effectiveness CUE, and Water Usage Effectiveness WUE.
Read the guide →Data Validation & AuditingData Validation Formula: Enforce Unique IDs & Approved Master-List Membership
Prevent duplicate badge/PO numbers AND rogue unapproved codes simultaneously using AND(COUNTIF($B$2:$B$6, B2) = 1, COUNTIF($E$2:$E$5, B2) > 0).
Read the guide →Data Validation & HygieneData Validation Restricting Dates to a Specific Year (ISNUMBER, INT & YEAR)
Enforce that entered journal dates are genuine numeric whole dates falling inside an authorized calendar or fiscal year, rejecting text strings, fractional timestamps, and out-of-period dates.
Read the guide →Data Validation & HygieneData Validation: Allow Letters and Numbers Only Without Punctuation or Spaces
Enforce strict ASCII alphanumeric input (A–Z, a–z, 0–9) with zero hyphens, spaces, or punctuation marks using an auditable CODE and MID character-range check.
Read the guide →Data Validation & HygieneData Validation: Reject Forbidden Substrings, Placeholders, or Disposable Domains
Block cell entries containing prohibited tokens such as "TBD", "test@", or disposable email domains case-insensitively using ISERROR(SEARCH(...)) rules.
Read the guide →Data Validation & HygieneData Validation: Require Cells to Contain a Specific Substring (SEARCH vs. FIND)
Enforce mandatory ticket prefixes, domain tags, or currency codes inside text inputs using ISNUMBER(SEARCH(...)) for case-insensitive rules or ISNUMBER(FIND(...)) for exact-case tokens.
Read the guide →Dates and reportingDATE function: build calendar dates from year, month, and day numbers
Construct unambiguous numeric dates from separate year, month, and day columns—and understand why DATE rolls invalid days like February 29, 2026 forward instead of raising an error.
Read the guide →Dates and reportingDATEDIF function: calculate completed years and remaining months
Measure service tenure in completed years ("Y") and leftover months ("YM") without double-counting total months ("M"), and catch reversed start/end dates (#NUM!).
Read the guide →Date & TimeDATEVALUE function: convert text dates to serial numbers safely
Turn imported ISO date strings into real spreadsheet serial dates with DATEVALUE, and guard mixed columns where some cells are already numeric dates.
Read the guide →Engineering & Fluid MechanicsDavies Equation Formula: Aqueous Ion Activity Coefficient Up to I = 0.5 mol/L
Extend Debye-Hückel electrolyte thermodynamics up to moderate ionic strength (I <= 0.5 M) without ion-size parameters using Cecil W. Davies’s 1962 equation log10(gamma_i) = -A * z_i² * (SQRT(I)/(1 + SQRT(I)) - 0.3 * I).
Read the guide →Operations, Logistics & EngineeringDaylight Hours (Photoperiod) Formula: Solar Declination & Sunrise-to-Sunset Duration
Calculate astronomical daylight duration N = (24 / PI()) * ACOS(-TAN(phi) * TAN(delta)) for any latitude phi and day-of-year J (1..365) using Cooper’s (1969) / FAO-56 solar declination equation, including 24-hour polar day and 0-hour polar night bounds.
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