Calculation Methodology
This page explains how the calculators on DuckworthLewisCalculator.com work, their assumptions and which inputs to use.
Run rate and required run rate
Current run rate = runs scored × 6 ÷ legal balls faced. Required run rate = (winning target − current runs) × 6 ÷ legal balls remaining. Cricket over notation counts six legal balls per over: 12.3 means 12 overs plus three deliveries, not 12.3 decimal overs.
Strike rate and economy
Batting strike rate = batter’s runs × 100 ÷ balls faced. Bowling economy = runs charged against the bowler × 6 ÷ legal balls bowled. Official scorecard conventions decide how extras are attributed.
Net run rate
NRR = (total runs scored × 6 ÷ total balls faced for NRR purposes) − (total runs conceded × 6 ÷ total balls bowled for NRR purposes). All-out innings and rain-affected games can require special denominator or score adjustments under tournament rules. Enter figures already adjusted to those rules.
Projected score
Projected score = runs so far × scheduled legal balls ÷ legal balls already faced. This is a straight-line pace estimate, not a forecast that accounts for wickets, conditions or innings strategy.
Duckworth–Lewis historical calculator
Our homepage tool uses the ICC-hosted historical 2002 over-by-over Duckworth–Lewis Standard Edition resource table. The percentage of remaining batting resources depends on both overs remaining and wickets lost. The calculator subtracts resources lost in a single rain interruption and determines a revised target based on each team’s resources. The historical G50 parameter is used when the chasing team has more available resources.
This implementation supports whole-over boundaries, a single interruption and common illustrative scenarios. It does not implement the modern professional DLS edition, repeated delays, partial overs, penalty adjustments or all competition-specific regulations.
Reference documents
- ICC: Duckworth–Lewis–Stern information
- ICC-hosted historical Standard Edition resource table
- ICC-hosted historical worked examples
Review and corrections
We check examples against stated source methodologies. If we discover an error, we aim to correct the tool and explanatory text and document substantive changes in this methodology page or the relevant calculator page.