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Round times or durations to 15-minute increments
Snap clock punches to the nearest quarter-hour (96 slots per day) or round billable duration upward to 15-minute increments.
Read the guide →MathRound to Nearest 10, 100, 1,000 or Million (Negative num_digits)
Round board-deck budgets, headcount forecasts, and property valuations to the LEFT of the decimal point using negative num_digits in ROUND(x, -3), ROUNDUP(x, -3), and ROUNDDOWN(x, -6).
Read the guide →Math & RoundingRound to Nearest Multiple (MROUND Pattern) vs. Up/Down Multiples (CEILING & FLOOR)
Round quantities, billing increments, and unit prices to the nearest, next-higher, or next-lower multiple of 5, 0.25, or carton pack size using ROUND, CEILING, and FLOOR.
Read the guide →MathRound Up or Down to Next Half (0.5), Quarter (0.25) or Custom Multiple
Round a numeric value upward, downward or to the nearest positive increment, with explicit input checks.
Read the guide →Numbers and totalsROUNDUP function: calculate how many boxes or packs are needed
Any leftover item requires another container. Divide item count by container capacity inside ROUNDUP(..., 0) so partial packs always round up to the next whole box.
Read the guide →Lookup & ReferenceROW and ROWS: create deletion-proof line numbers and count table height
Distinguish position index ROW(reference) from range height ROWS(array) so inserted or blank rows never break numbering.
Read the guide →Math & TrigonometryRow-Wise and Column-Wise Matrix Summaries and Flags (BYROW & BYCOL Formula Patterns)
Evaluate row-by-row totals, minimum-threshold SLA flags, and column-by-column period peaks across 2D matrices using CHOOSEROWS, CHOOSECOLS, and helper vectors.
Read the guide →Healthcare & ClinicalROX Index for HFNC Failure & Rapid Shallow Breathing Index (RSBI = f / VT)
Calculate the Roca ROX Index (SpO2 / FiO2) / RR to predict high-flow nasal cannula (HFNC) intubation risk and the Yang-Tobin Rapid Shallow Breathing Index RSBI = RR / VT_L for ventilator weaning.
Read the guide →Labor Economics & Policy EconometricsRoy Self-Selection Positive vs Negative Sorting Formula
Diagnose Andrew Roy’s (1951) and George Borjas’s (1987) occupational/migration skill selection via covariance wedges Cov(u_1, u_1 - u_0) and Cov(u_0, u_1 - u_0).
Read the guide →Labor Economics & EconometricsRoy-Borjas Migration Self-Selection Skill Sorting Formula
Classify Positive Selection, Negative Selection, and Refugee Sorting using Borjas’s (1987) Roy-model conditional log-wage selection terms Q_0 and Q_1.
Read the guide →Rubber & Tire Molding, Sulfur/Peroxide Vulcanization Kinetics & ASTM D5289 MDR t90Rubber Vulcanization Equivalent Cure Units (ECU) Formula
Calculate Arrhenius Crosslinking Rate Multiplier vs Reference Temperature, Equivalent Cure Time t90(T) in Minutes and Seconds, and Press Cycle Time Saved (min).
Read the guide →Civil, Structural & Geotechnical EngineeringRubey (1933) Sediment Fall Velocity Formula: HEC-RAS Dimensionless Factor F_1 & Settling
Calculate river sand and gravel terminal settling velocity w_s = F_1 * SQRT((s - 1) * g * D) using USGS geologist William W. Rubey’s (1933) analytical viscous-plus-impact quadratic drag formula built into USACE HEC-RAS.
Read the guide →Game Theory & Strategic NegotiationRubinstein Alternating-Offers Bargaining Equilibrium Formula
Calculate Rubinstein’s (1982) unique subgame-perfect bargaining split x_1* = S * (1 - delta_2) / (1 - delta_1 * delta_2) to quantify patience vs first-mover advantage.
Read the guide →Quantitative Finance & DerivativesRubinstein Simple Chooser Option Formula: Call-or-Put Decision Date
Price a simple chooser option in Excel and Arte Sheets via Rubinstein’s (1991) put-call parity decomposition into a T-maturity call plus a t_c-maturity shifted-strike put.
Read the guide →FinancialRule of 72 vs exact doubling & tripling time formula (LN(2) / LN(1 + r))
Calculate exact compound doubling time LN(2)/LN(1+r), continuous doubling LN(2)/r, and N-fold multiplication time—and see where Rule of 72 drifts.
Read the guide →FinancialRule of 78s interest allocation: rebate and straight-line comparison
Illustrate sum-of-digits allocation for a precomputed finance charge. Compare with straight-line allocation, not an actuarial payoff calculation.
Read the guide →Math & TrigRunning balance with debits and credits (checkbook and ledger formula)
Maintain a cumulative bank or ledger balance across separate Deposit and Withdrawal columns while hiding totals on unposted rows.
Read the guide →StatisticalRunning count of occurrences in a list (1st, 2nd, 3rd repeat)
Number each appearance of a customer or SKU sequentially down a table with SUMPRODUCT(--($A$2:A2=A2)) and build unique composite keys.
Read the guide →FinancialRunning Cumulative Balance, Compound Wealth Index, and High-Water Mark (SCAN & REDUCE Formulas)
Generate step-by-step intermediate accumulator states (running cash balance, compounded wealth index, and running high-water mark) alongside terminal totals.
Read the guide →Lookup & ReferenceRunning Occurrence Count by Customer or SKU (Expanding COUNTIF)
Number each repeat occurrence of an item sequentially (1st, 2nd, 3rd order per customer) using an anchored expanding range =COUNTIF($A$2:A2, A2) and build unique composite lookup keys.
Read the guide →Process Safety, ASME Section VIII UG-127 & Rupture DisksRupture Disk Manufacturing Range, Hot Burst & Kc Formula
Calculate Rupture Disk Upper Stamped 72°F Burst Rating (psig), Elevated-Temperature Maximum Burst Pressure (psig), ASME UG-127 Combination Derated PRV Capacity (lb/hr), and MAWP Margin (psi).
Read the guide →Chemical & Pharmaceutical Solid-Liquid Separation, Ruth Cake Filtration & Filter PressRuth Constant-Pressure Cake Filtration Time Formula
Calculate Total Dry Filter Cake Deposited (kg), Parabolic Cake-Resistance Filtration Time (min), Linear Filter-Cloth Resistance Time (min), and Total Cycle Filtration Time (min).
Read the guide →FinancialSaaS cohort retention table: mixed-reference retention % and weighted cohort average
Divide active customers in Month 1, 2, 3... by locked Month-0 cohort size ($B2) while hiding unelapsed triangle cells.
Read the guide →SaaS Metrics, Venture Growth Benchmarks & Cohort Retention EconomicsSaaS Gross Revenue Retention (GRR) & Bessemer Score Formula
Calculate Enterprise SaaS Gross Revenue Retention (GRR <= 100%), Net Dollar Retention (NDR), Bessemer Venture Partners Capital Efficiency Score (Net New ARR / Net Burn), and Ending Total ARR ($M).
Read the guide →FinancialSaaS MRR waterfall: Ending MRR, Gross Retention (GRR), and Net Dollar Retention (NDR)
Reconcile Starting, New, Expansion, Contraction, and Churned MRR and compute commonly used GRR and NDR percentages.
Read the guide →FinancialSaaS Quick Ratio & Net New MRR / ARR waterfall formula (growth vs churn)
Measure subscription growth efficiency via (New MRR + Expansion MRR) / (Churned MRR + Contraction MRR) alongside Net New ARR.
Read the guide →SaaS FP&A & ASC 606 Revenue AccountingSaaS RPO, Calculated Billings & Book-to-Bill Formula
Reconcile ASC 606 / IFRS 15 Calculated Billings (Revenue + Delta Deferred Revenue), Remaining Performance Obligations (RPO = Deferred Revenue + Unbilled Backlog), Contracted Net Bookings, and RPO Book-to-Bill.
Read the guide →FinancialSaaS Rule of 40, Magic Number, and Burn Multiple formulas
Benchmark SaaS growth efficiency using Rule of 40 (Growth % + FCF Margin %), Go-to-Market Magic Number, and Capital Burn Multiple.
Read the guide →Power-to-Gas (PtG), E-Methane & Carbon Utilization EngineeringSabatier CO2 Methanation H2 Demand, SNG & Heat Recovery Formula
Calculate Stoichiometric Green H2 Feed (kg/hr), Synthetic Natural Gas CH4 Output (kg/hr), Condensed Byproduct Water (kg/hr), and Exothermic Reactor Steam Duty (MWth).
Read the guide →EngineeringSabine & Eyring Reverberation Time (RT60) Room Acoustics Formulas
Compare Sabine and Eyring diffuse-field reverberation estimates using room volume, total surface area and a frequency-specific average absorption coefficient.
Read the guide →Engineering & ScienceSackur-Tetrode Equation: Absolute Quantum Molar Entropy of Monatomic Gases
Calculate the absolute statistical-mechanics molar entropy S_m = R * (1.5*LN(M) + 2.5*LN(T) - LN(P_bar) - 1.15171) (J/(mol·K)) of noble gases directly from Planck’s constant!
Read the guide →Corrosion Engineering, Subsea Pipelines & Offshore StructuresSacrificial-Anode Cathodic Protection Mass & Count Formula
Calculate DNV-RP-B401 Galvanic Cathodic Protection Mean Current Demand (A), Required Net Anode Mass (kg), Minimum 150 kg Al-Zn-In Anode Count, and Gross Installed Anode Mass (kg).
Read the guide →StatisticalSafety stock formula: combine demand volatility and supplier lead-time variance
Size warehouse safety stock for 95% or 99% cycle service levels using Z * SQRT(AvgLeadTime * DemandSD^2 + AvgDemand^2 * LeadTimeSD^2).
Read the guide →Mineral Comminution, SAG/Ball Grinding Mills & Liner MechanicsSAG & Ball Mill Critical Centrifuging Speed (%Nc) Formula
Calculate Effective Ball-Center Orbit Diameter (D - d), Critical Centrifuging Speed N_c (RPM), Operating Percent Critical Speed (%Nc), and Grinding Motion Regime.
Read the guide →Engineering & ScienceSagnac Interferometer Phase Shift Formula (Fiber-Optic Gyroscope FOG)
Calculate counter-propagating laser Sagnac phase shift Δφ = (2 * π * L * D * Ω_rad_s) / (λ * c) (radians) in aerospace and subsea inertial navigation fiber-optic gyroscopes.
Read the guide →ScienceSaha Thermal Ionization Equation (Stellar & Laboratory Plasma)
Estimate the ionized fraction of pure atomic hydrogen in a ground-state LTE approximation. Use a log-domain Saha ratio and a stable quadratic solution to avoid cancellation at high ionization.
Read the guide →Engineering & ScienceSaha Thermal Ionization Equation & Plasma Ionization Fraction (x)
Calculate the dimensionless Saha equilibrium constant K_Saha and quadratic plasma ionization degree x = (-K + SQRT(K^2 + 4*K)) / 2 for stellar atmospheres (A0 stars) and ICP spectroscopy.
Read the guide →Mechanical & Structural EngineeringSaint-Venant Rectangular Bar Torsion Constant and Peak Shear Stress
Avoid the circular polar-inertia J_p trap on rectangular shafts by computing Saint-Venant torsional stiffness K_tor, twist angle, and midpoint long-side peak shear stress.
Read the guide →CMOS Digital Design & Low-Power ElectronicsSakurai Alpha-Power CMOS Delay & EDP Formula
Calculate CMOS Dynamic Switching Energy E_dyn = C_L * V_DD^2, Sakurai Velocity-Saturated Propagation Delay t_p = 0.5 * C_L * V_DD / (K_d * (V_DD - V_th)^alpha), Shockley Square-Law Bias, and Energy-Delay Product (EDP).
Read the guide →StatisticalSalary benchmarking formulas: Compa-Ratio, Range Penetration, and Percentile Rank
Compare salary with a defined band midpoint and range, and calculate a rank within the example peer set.
Read the guide →Charts & Visual DataSales Funnel Chart Formula: Invisible Centering Spacer & Stage Drop-Off %
Construct a centered horizontal Sales Funnel on any stacked bar chart by computing the exact left-padding spacer (Top_Stage - Stage_i) / 2 alongside stage-to-stage conversion and leakage rates.
Read the guide →SaaS RevOps & FP&A Capacity PlanningSales Rep Ramp Quota Capacity & Attrition Formula
Calculate Ramped Rep Equivalents (RRE), Street Quota Capacity, and Attrition-Adjusted Expected Bookings against Board ARR targets using SUMPRODUCT.
Read the guide →Finance & AccountingSales Tax Rate Lookup with Tax-Exempt Override (XLOOKUP + IF)
Calculate invoice sales tax and gross total dynamically by combining IF(Tax_Exempt = "Yes", 0, XLOOKUP(...)) with missing-jurisdiction validation.
Read the guide →Healthcare & Clinical FormulasSALT Score (Severity of Alopecia Tool) Weighted Scalp Quadrant Formula
Calculate Elise Olsen’s NAAF Severity of Alopecia Tool score SALT = 0.18*Left + 0.18*Right + 0.40*Top + 0.24*Back (0–100%) and classify JAK-inhibitor trial eligibility (SALT >= 50) vs SALT <= 20 treatment response.
Read the guide →Healthcare & Clinical FormulasSAMe-TT2R2 Score: Warfarin INR Quality (TTR) vs Upfront DOAC Selection
Calculate Stavros Apostolakis’ 0–8 SAMe-TT2R2 anticoagulation choice score (Sex female +1, Age <60 +1, Medical history >2 comorbidities +1, Interacting Rx like amiodarone +1, Tobacco within 2 yrs +2, Non-Caucasian Race +2) to predict poor warfarin INR control.
Read the guide →Quantitative FinanceSample & Population Covariance Formula (COVARIANCE.S / .P) & CAPM Beta
Calculate Population Covariance Cov_P = CORREL(X, Y) * STDEV.P(X) * STDEV.P(Y), Bessel-corrected Sample Covariance Cov_S = CORREL(X, Y) * STDEV.S(X) * STDEV.S(Y), and CAPM Market Beta = Cov(R_i, R_m) / Var(R_m).
Read the guide →Statistical AnalysisSample & Population Excess Kurtosis (KURT Fourth-Moment Tail Risk Formula)
Compute unbiased Fisher sample excess kurtosis (KURT) and population excess kurtosis from standardized fourth moments to detect fat-tailed (leptokurtic) vs thin-tailed (platykurtic) series.
Read the guide →Statistical & AggregationSample & Population Skewness Formulas (SKEW vs SKEW.P Third Standardized Moment)
Measure distribution asymmetry and tail direction using both the adjusted Fisher-Pearson sample skewness (SKEW, requiring n >= 3) and population skewness (SKEW.P) built from SUMPRODUCT, AVERAGE, STDEV.S, and STDEV.P.
Read the guide →Healthcare & Clinical CalculationsSampson-NIH Equation 2 LDL Cholesterol Calculator (TG up to 800 mg/dL)
Calculate beta-quantification-calibrated LDL cholesterol (mg/dL) up to triglycerides of 800 mg/dL using Maureen Sampson’s bivariate NIH Equation 2 and measure Friedewald underestimation bias.
Read the guide →Healthcare & ClinicalSampson-NIH LDL-C Equation (Accurate LDL up to Triglycerides 800 mg/dL)
Calculate low-density lipoprotein cholesterol (LDL-C) in mg/dL using the 2020 Sampson-NIH bivariate quadratic equation—avoiding Friedewald's underestimation at low LDL-C or triglycerides up to 800 mg/dL.
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